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<!-- DFIN New ActiveDisclosure (SM) XBRL Linkbase Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date :2023-03-14T14:41:46.4440+00:00 -->
<!-- Copyright (c) 2023 Donnelly Financial Solutions, Inc. All Rights Reserved. -->
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_IL" xlink:label="country_IL"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTextBlock" xlink:label="us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTextBlock"/>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments, Gain (Loss) [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, City or Town</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, City or Town</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchasedDuringPeriodValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value of shares repurchased</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchasedDuringPeriodValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Repurchased During Period, Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reconciliation of Company's Effective Tax Rate to U.S. Federal Statutory Rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsInterestLossAndCreditCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest, loss, and credit carryforwards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsInterestLossAndCreditCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred tax assets interest, loss, and credit carryforwards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsInterestLossAndCreditCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets interest, loss, and credit carryforwards.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PaymentsOfFinanceLeases_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments of finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PaymentsOfFinanceLeases_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments Of Finance Leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PaymentsOfFinanceLeases_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments of finance leases.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income per share:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 1 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsNetIncludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Intangible Assets, Net (Including Goodwill), Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsNetIncludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill and intangible assets, net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsNetIncludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Intangible Assets, Net (Including Goodwill)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Three</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BaseRateBorrowingsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Base Rate Borrowings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BaseRateBorrowingsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Base Rate Borrowings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BaseRateBorrowingsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Base rate borrowings member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from financing activities:</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeTradeDates_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade Date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeTradeDates_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Trade Dates</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeTradeDates_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Derivative trade dates.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsAccruedExpensesAndOtherReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses and other reserves</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsAccruedExpensesAndOtherReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Accrued Expenses And Other Reserves</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsAccruedExpensesAndOtherReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets accrued expenses and other reserves.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeInstrumentsGainLossNotDesignatedAsHedgingInstrumentsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Instruments Gain Loss Not Designated As Hedging Instruments [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeInstrumentsGainLossNotDesignatedAsHedgingInstrumentsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments Gain Loss Not Designated As Hedging Instruments [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeInstrumentsGainLossNotDesignatedAsHedgingInstrumentsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Derivative Instruments Gain Loss Not Designated As Hedging Instruments [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeAssetNotionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Gross notional values of outstanding forward foreign exchange contracts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeAssetNotionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Currency Hedged (Buy/Sell), Gross Notional Value, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeAssetNotionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Asset, Notional Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReportingUnitAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reporting Unit [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Borrowings outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-Term Line of Credit, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total borrowings outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Line of Credit</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OptionAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Option Agreement [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OptionAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Option Agreement [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OptionAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Option agreement.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanExpectedFutureBenefitPaymentsForNextTenYears_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Estimated benefit payments for next 10 years, total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanExpectedFutureBenefitPaymentsForNextTenYears_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments For Next Ten Years</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanExpectedFutureBenefitPaymentsForNextTenYears_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan expected future benefit payments for next ten years.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amendment Flag</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Flag</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year Four</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total fair value of RSUs vested</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Event Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermBorrowings_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Short-Term Debt, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermBorrowings_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Short term debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermBorrowings_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermBorrowings_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated Amortization</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Accumulated Amortization</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfSalesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of Revenues [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfSalesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Sales [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionSharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Price per share of common stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionSharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition, Share Price</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Goodwill, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance, Goodwill Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance, Goodwill Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarJapaneseYenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Dollar/Japanese Yen [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarJapaneseYenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">U S Dollar Japanese Yen [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarJapaneseYenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">U S Dollar Japanese Yen [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Right-of-use assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Right-of-Use Asset</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="exch_JPBX_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Japan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="exch_JPBX_lbl" xlink:role="http://www.xbrl.org/2003/role/label">JPBX [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Components of Intangible Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Finite-Lived Intangible Assets [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SupplementalRetirementBenefitsCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Supplemental retirement benefits cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SupplementalRetirementBenefitsCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Supplemental Retirement Benefits Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SupplementalRetirementBenefitsCost_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Supplemental retirement benefits cost.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PostemploymentBenefitsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Postemployment Benefits [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Long-Term Debt Instruments [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sales of investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Sale of Debt Securities, Available-for-Sale</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermDebtLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short Term Debt [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermDebtLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Debt [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEC Schedule, 12-09, Valuation Allowances and Reserves</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: imputed interest</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, Undiscounted Excess Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Income Per Share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockIncentivePlanTwoThousandTwentyTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock Incentive Plan 2022 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockIncentivePlanTwoThousandTwentyTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Incentive Plan Two Thousand Twenty two [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockIncentivePlanTwoThousandTwentyTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock incentive plan two thousand twenty two.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FederalFundsRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal Funds Rate [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FederalFundsRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Federal Funds Rate [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FederalFundsRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Federal funds rate.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year One</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PrepaymentPremiumPercentageOfAggregatePrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepayment premium percentage of aggregate principal amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PrepaymentPremiumPercentageOfAggregatePrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepayment Premium Percentage of Aggregate Principal Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PrepaymentPremiumPercentageOfAggregatePrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prepayment premium percentage of aggregate principal amount.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InitialCommitmentFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Initial commitment fee percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InitialCommitmentFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Initial Commitment Fee Percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InitialCommitmentFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Initial commitment fee percentage.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeasePayments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating cash flows used for operating leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeasePayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Payments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BenefitOfTheTaxIncentivePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Benefit of the tax incentive per share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BenefitOfTheTaxIncentivePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Benefit Of The Tax Incentive Per Share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BenefitOfTheTaxIncentivePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Benefit of the tax incentive per share.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ServiceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Services [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ServiceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Service [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncurrentLiabilitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Noncurrent Liabilities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncurrentLiabilitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Noncurrent Liabilities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Preferred Stock, Shares Outstanding, Ending Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Preferred Stock, Shares Outstanding, Beginning Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Machinery and Equipment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Machinery and Equipment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Charged to expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restructuring Charges, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Charges</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementThreeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Swap Agreement Three [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementThreeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement Three [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementThreeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Swap agreement three.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock reserved for issuance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Capital Shares Reserved for Future Issuance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Dividend payments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividend payment to common shareholders</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments of Ordinary Dividends, Common Stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockNoParValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, par value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockNoParValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, No Par Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorFirmId_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Auditor Firm ID</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorFirmId_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Firm ID</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">RSUs, Weighted Average Grant Date Fair Value, Beginning of period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">RSUs, Weighted Average Grant Date Fair Value, end of period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Average Grant Date Fair Value, Vested</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventories</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in value of financial instruments designated as cash flow hedges</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NatureOfOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Description</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NatureOfOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nature of Operations [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Disclosure [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning Balance, Shares</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance, Shares</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares, Issued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Tax Authority</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Authority [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Expected Future Benefit Payment, Year Four</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Windfall tax effect on stock-based compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expense, Tax Benefit</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_HedgingRelationshipDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hedging Relationship</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_HedgingRelationshipDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Hedging Relationship [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAcquiredDuringPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquired goodwill, Gross Carrying Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAcquiredDuringPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill Acquired During Period Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAcquiredDuringPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Goodwill acquired during period gross.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EquipmentSolutionsBusinessMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equipment Solutions Business [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EquipmentSolutionsBusinessMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equipment Solutions Business [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EquipmentSolutionsBusinessMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Equipment Solutions Business [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FinanceLeaseCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FinanceLeaseCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FinanceLeaseCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Finance lease costs.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNonCurrentAccruedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-current accrued compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNonCurrentAccruedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Non-current Accrued Compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNonCurrentAccruedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination recognized identifiable assets acquired and liabilities assumed non-current accrued compensation.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Acquired intangible assets, estimated useful lives</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible assets amortized period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Useful Life</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Employee-related Liabilities, Current, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee-related Liabilities, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Leases [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Type [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net issuance under stock-based plans, Shares</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AmortizationPeriodOfLeaseholdImprovements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization period of leasehold improvements</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AmortizationPeriodOfLeaseholdImprovements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization Period Of Leasehold Improvements</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AmortizationPeriodOfLeaseholdImprovements_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amortization period of leasehold improvements.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted-average remaining lease term in years-operating leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average remaining lease term-operating leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Weighted Average Remaining Lease Term</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities and stockholders' equity</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewTermLoanFacilityNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">New Term Loan Facility, Net [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewTermLoanFacilityNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">New Term Loan Facility, Net [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewTermLoanFacilityNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">New term loan facility, net member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventories</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Other Comprehensive Income (Loss) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">AOCI Including Portion Attributable to Noncontrolling Interest [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net gain (loss) reclassified from accumulated OCI into income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pension assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets for Plan Benefits, Defined Benefit Plan</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedPeriodStartLabel">Beginning balance, Accumulated Impairment Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedPeriodEndLabel">Ending balance, Accumulated Impairment Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill, Impaired, Accumulated Impairment Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaterialsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">MSD [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaterialsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Materials Solutions Division [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaterialsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Materials solutions division [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaterialsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Materials solutions division.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-current deferred taxes</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Denominator:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average common shares outstanding:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Diluted [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FirstLienNetLeverageRatioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">First Lien Net Leverage Ratio [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FirstLienNetLeverageRatioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">First Lien Net Leverage Ratio [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FirstLienNetLeverageRatioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">First lien net leverage ratio member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lam Research Corporation [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer One [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer one.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementSevenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement Seven [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementSevenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Swap Agreement Seven.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Incorporation, State or Country Code</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Incorporation, State or Country Code</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LongTermInvestmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long Term Investments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LongTermInvestmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Investments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LongTermInvestmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Long Term Investments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForTenOrMorePercentOfAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of customers</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForTenOrMorePercentOfAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Customers Accounted For Ten Or More Percent Of Accounts Receivable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForTenOrMorePercentOfAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of customers accounted for ten or more percent of accounts receivable.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basis of Presentation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted-average remaining lease term in years-finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average remaining lease term-finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Weighted Average Remaining Lease Term</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other non-current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Photon Control [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Photon Control [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Photon Control.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Liability</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Segments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Segments [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RevenueRecognitionPaymentTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Company's normal payment terms</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RevenueRecognitionPaymentTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Recognition Payment Terms</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RevenueRecognitionPaymentTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Revenue recognition payment terms.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsLoanCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loan costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsLoanCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Loan Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxAssetsLoanCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets loan costs.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition Accounting</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combinations Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarKoreanWonMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Dollar/South Korean Won [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarKoreanWonMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">U S Dollar Korean Won [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarKoreanWonMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">U S Dollar Korean Won [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Three</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPeriodDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share based compensation arrangement by share based payment award vesting period description</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPeriodDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Vesting Period Description</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPeriodDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award vesting period description.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year Five</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAcquiredFromAcquisition_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less: Cash and cash equivalents acquired</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAcquiredFromAcquisition_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Acquired from Acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Acquisition, Acquiree</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition, Acquiree [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwardsExpirationDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards expiration date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwardsExpirationDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards, Expiration Date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Measurements, Recurring [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Recurring [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Interest Expense, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade Names [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trade Names [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement Eight [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Swap Agreement Eight.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeNotionalAmountAtEffectiveDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notional Amount at Effective Date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeNotionalAmountAtEffectiveDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Notional Amount At Effective Date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeNotionalAmountAtEffectiveDate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Derivative notional amount at effective date.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermLeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term lease</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermLeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Lease, Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reconciliation of Segment Assets to Consolidated Total Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reconciliation of Assets from Segment to Consolidated [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OfferTerminateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offer Terminate [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OfferTerminateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Offer Terminate [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OfferTerminateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">OfferTerminate Member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Instruments and Hedging Activities Disclosures [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments and Hedging Activities Disclosures [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares authorized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Authorized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Liabilities, Net, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel">Net deferred tax (liabilities) assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsRecordedToCorrectOverstatementOfIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Adjustments recorded to correct overstatement of intangible assets, net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsRecordedToCorrectOverstatementOfIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments Recorded to Correct Overstatement of Intangible Assets, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsRecordedToCorrectOverstatementOfIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Adjustments recorded to correct overstatement of intangible assets, net.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total debt, excluding deferred financing costs, fair value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewRevolvingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">New Revolving Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewRevolvingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">New Revolving Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewRevolvingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">New revolving facility member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total long-term assets</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non current assets fair value disclosure.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Components of Income Before Income Taxes and Related Provision (benefit) for Income Taxes</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted-average discount rate-operating leases</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable Rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Variable Rate [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntitySmallBusiness_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Small Business</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntitySmallBusiness_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Small Business</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TimeDepositsAndCertificatesOfDepositMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Time Deposits and Certificates of Deposit [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TimeDepositsAndCertificatesOfDepositMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Time Deposits and Certificates of Deposit [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of reportable segments</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PensionAndDeferredCompensationPlanAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Pension and deferred compensation plan assets.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligationOptionalExemptionRemainingDuration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Remaining performance obligation period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligationOptionalExemptionRemainingDuration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Remaining Performance Obligation, Optional Exemption, Remaining Duration</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Exchange Forward Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Foreign Exchange Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Exchange Forward [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SeparatelyPricedContractsTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term of separately priced contracts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SeparatelyPricedContractsTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Separately Priced Contracts Term</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SeparatelyPricedContractsTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Separately priced contracts term.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ValuationAndQualifyingAccountsDisclosureLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanVestedBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined benefit plan, vested benefit obligations</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanVestedBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Vested Benefit Obligation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanVestedBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan vested benefit obligation.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockIncentivePlanTwoThousandFourteenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock Incentive Plan 2014 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockIncentivePlanTwoThousandFourteenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Incentive Plan Two Thousand Fourteen [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockIncentivePlanTwoThousandFourteenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock Incentive Plan Two Thousand Fourteen</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hedging Relationship</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Hedging Relationship [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReportingUnitDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reporting Unit [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateFloorMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Floor Rate [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateFloorMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Floor [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringAndRelatedActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring and Related Activities [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restructuring Reserve, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Balance at January 1</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance at December 31</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Reserve</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Net Revenues and Long-Lived Assets by Geographic Regions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Redemption, Period [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrualNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term product warranties</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrualNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product Warranty Accrual, Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Deferred Revenue and Customer Advances by Arrangement</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Indefinite-lived Intangible Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Indefinite-Lived Intangible Assets [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TrademarksAndTradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Trademarks and Trade Names [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TrademarksAndTradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trademarks and Trade Names [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TrademarksAndTradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trademarks and Trade Names [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Un-amortized intangible assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Indefinite-Lived Intangible Assets (Excluding Goodwill), Ending Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Indefinite-Lived Intangible Assets (Excluding Goodwill), Beginning Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Indefinite-Lived Intangible Assets (Excluding Goodwill), Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Indefinite-Lived Intangible Assets (Excluding Goodwill)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShortTermDebtTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Short Term Debt [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShortTermDebtTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Short-Term Debt [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Other Operating Liabilities, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current and non-current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Operating Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted Average Number of Shares Outstanding, Basic, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Shares used in net income per common share &#8211; basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsToAdditionalPaidInCapitalSettlementOfShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Settlement of share-based compensation awards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsToAdditionalPaidInCapitalSettlementOfShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments To Additional Paid In Capital Settlement Of Share Based Compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsToAdditionalPaidInCapitalSettlementOfShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Adjustments To Additional Paid In Capital Settlement Of Share Based Compensation.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total lease liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease liabilities</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">City Area Code</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDebtTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Outstanding Debt</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForTenOrMorePercentOfRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of customers accounted for 10% or more of total revenue</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForTenOrMorePercentOfRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of customers accounted for ten or more percent of revenue.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonicsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Photonics Solutions Division [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonicsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">PSD [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonicsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Photonics Solutions Division [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonicsSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Photonics solutions division.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Net Periodic Benefit Costs</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Euro tranche B member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAmortizationOfActuarialGainLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan amortization of actuarial gain loss.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Period End Date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Period End Date</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash dividends per common share</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Finite-Lived Intangible Assets [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConstructionInProgressMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction in Progress [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConstructionInProgressMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Construction in Progress [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net periodic benefit costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Net Periodic Benefit Cost (Credit)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Investments, Gross Unrealized (Losses)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale and Held-to-Maturity, Cumulative Unrecognized Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign currency translation adjustments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Executive supplemental retirement benefits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Revenues, Assets and Goodwill by Reportable Segment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Segment Reporting Information, by Segment [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based Compensation Award, Tranche One [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Tranche One [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term deferred revenue</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Liability, Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividend declared date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Dividends Payable, Date Declared</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncrementalTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncrementalTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Incremental Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncrementalTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Incremental Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncrementalTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Incremental Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Expected Amortization, Year One</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PriorTermLoanFacilityNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prior Term Loan Facility, Net [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PriorTermLoanFacilityNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prior Term Loan Facility, Net [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PriorTermLoanFacilityNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prior term loan facility, net.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsdTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">USD Tranche B [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsdTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">USD Tranche B [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsdTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">USD Tranche B member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Expected Future Benefit Payment, Year One</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ExpenseOfRestructuringActivitiesAndOtherAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Expense Of Restructuring Activities And Other [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ExpenseOfRestructuringActivitiesAndOtherAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Expense Of Restructuring Activities And Other [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseInterestPaymentOnLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating cash flows used for finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseInterestPaymentOnLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Interest Payment on Liability</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Expected Amortization, after Year Five</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligationNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated benefit obligation noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligationNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Supplemental Retirement Benefits Accumulated Benefit Obligation Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligationNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Supplemental retirement benefits accumulated benefit obligation noncurrent.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfSharesReturnedForEachShareOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares returned for each common stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfSharesReturnedForEachShareOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Shares Returned For Each Share Of Common Stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfSharesReturnedForEachShareOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Shares Returned For Each Share Of Common Stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidated total assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total net revenues</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Contract with Customer, Asset, after Allowance for Credit Loss, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Asset, after Allowance for Credit Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Contract</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Contract [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="country_DE_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Germany [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="country_DE_lbl" xlink:role="http://www.xbrl.org/2003/role/label">GERMANY</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Euro Tranche [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Euro Tranche</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Euro Tranche [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Euro tranche.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee contribution to Company's profit sharing plan percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total debt, excluding deferred financing costs, carrying value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Excluding Current Maturities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-Term Debt, Excluding Current Maturities, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Diluted, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Diluted</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Diluted</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetirementPlanTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retirement Plan Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetirementPlanTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Plan Type [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Current Assets Fair Value Disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other current assets fair value disclosure.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Rate of increase in salary levels</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Postal Zip Code</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Postal Zip Code</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrealizedGainLossOnDerivatives_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Unrealized loss (gain) on derivatives not designated as hedging instruments</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasicAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income per common share:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasicAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountPercentageOfPrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Original issue discount percentage of principal amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountPercentageOfPrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Original Issue Discount Percentage of Principal Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountPercentageOfPrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Original issue discount percentage of principal amount.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product Warranties</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Period Focus</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LaserProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lasers Products [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LaserProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Laser Products [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LaserProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Laser products.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cost of Goods and Services Sold, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of revenues</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Goods and Services Sold</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finite Lived Intangible Assets Acquired As Part Of Business Combination [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OfficeEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Office Equipment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OfficeEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Office Equipment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Current taxes, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Income Tax Expense (Benefit)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllowanceForSalesReturnMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation Allowance for Sales Returns [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllowanceForSalesReturnMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Allowance For Sales Return [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllowanceForSalesReturnMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Allowance for sales return.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Trade accounts receivable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Receivable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revolving Lines of Credit [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revolving Credit Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Valuation allowance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Valuation Allowance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, $0.01 par value, 2 shares authorized; none issued and outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Value, Issued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Five</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effect of dilutive securities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UnrecognizedTaxBenefitsIncreaseDecreaseResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increases for tax positions taken during prior years</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UnrecognizedTaxBenefitsIncreaseDecreaseResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits Increase Decrease Resulting From Prior Period Tax Positions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UnrecognizedTaxBenefitsIncreaseDecreaseResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Unrecognized tax benefits increase decrease resulting from prior period tax positions.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockholdersEquityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders Equity [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockholdersEquityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders Equity [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockholdersEquityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stockholders Equity [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Operating Lease, Liability, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total lease liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash provided by (used in) financing activities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Financing Activities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Applied Materials, Inc. [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Two [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer two.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestrictedStockUnitsGrantedToEmployeesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">RSUs Granted to Employees [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestrictedStockUnitsGrantedToEmployeesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock Units Granted To Employees [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestrictedStockUnitsGrantedToEmployeesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Restricted Stock Units Granted To Employees [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Financial Position [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyContractAssetFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives-foreign currency options</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyContractAssetFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Currency Contract, Asset, Fair Value Disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated Impairment Charges</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment of Intangible Assets, Indefinite-Lived (Excluding Goodwill)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity File Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Securities Act File Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxLiabilitiesLoanCosts_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Loan costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxLiabilitiesLoanCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities Loan Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxLiabilitiesLoanCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax liabilities loan costs.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AnnualStepDownMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Annual Step-Down [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AnnualStepDownMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Annual Step-Down [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AnnualStepDownMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Annual step-down member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scenario</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease payments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net (loss) gain recognized in income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPeriodOfCompanysResearchAndDevelopmentProjects_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum period of company's research and development projects</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPeriodOfCompanysResearchAndDevelopmentProjects_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum Period Of Companys Research And Development Projects</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPeriodOfCompanysResearchAndDevelopmentProjects_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Minimum period of company's research and development projects.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroUsDollarMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Euro US dollar [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroUsDollarMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Euro/U.S. dollar.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Cash Flows [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GuaranteesAndProductWarrantiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Guarantees and Product Warranties [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, after Year Five</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanDebtSecurityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Securities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanDebtSecurityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Debt Security [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Allocation of Acquired Intangible Assets and Related Estimates of Useful Lives</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherCurrentLiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherCurrentLiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other current liabilities fair value disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherCurrentLiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other current liabilities fair value disclosure.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BuildingAndBuildingImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Building and Building Improvements [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BuildingAndBuildingImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Building and Building Improvements [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeAssetAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Derivatives-interest rate hedge-non-current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeAssetAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives assets interest rate hedge-non-current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeAssetAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Current Interest Rate Fair Value Hedge Asset At Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeAssetAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non current interest rate fair value hedge asset at fair value.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEC Schedule, 12-09, Valuation Allowances and Reserves Type</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_SegmentGeographicalDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographical</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_SegmentGeographicalDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Geographical [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TaxCreditCarryForwardExpirationYearEnd_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax credit expiration period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TaxCreditCarryForwardExpirationYearEnd_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax Credit Carry Forward Expiration Year End</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TaxCreditCarryForwardExpirationYearEnd_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tax credit carry forward expiration year end.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Price Range</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Stockholders' Equity [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_VacuumSolutionsDivisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Vacuum solutions division.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTaxAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Comprehensive income (net of tax):</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorLocation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Auditor Location</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCurrentLiabilitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Current Liabilities [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfCapitalExpenditureDepreciationAndAmortizationAndAssetsReportableSegmentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Capital Expenditures, Depreciation and Amortization Expense of Intangible Assets by Reportable Segment</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfCapitalExpenditureDepreciationAndAmortizationAndAssetsReportableSegmentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of capital expenditure depreciation and amortization and assets reportable segments.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarSingaporeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Dollar/Singapore Dollar [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarSingaporeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">U S Dollar Singapore [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarSingaporeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">U S Dollar Singapore.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sales Revenue, Net [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Benchmark [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additions Charged to Costs and Expenses</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllocatedShareBasedCompensationEffectOnEarningPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Diluted</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllocatedShareBasedCompensationEffectOnEarningPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Allocated Share Based Compensation Effect On Earning Per Share Diluted</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllocatedShareBasedCompensationEffectOnEarningPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Allocated share based compensation effect on earning per share diluted.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue from Contracts with Customers</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Elements of Lease Payments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease, Cost [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Work-in-process</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Expected Future Benefit Payment [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SignificantSupplyCommitmentTimePeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Significant Supply Commitment Time Period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SignificantSupplyCommitmentTimePeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase commitments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other comprehensive income, net of tax:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingStandardsUpdate201409Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounting Standards Codification Topic 606 adjustment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingStandardsUpdate201409Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Standards Update 2014-09 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationChangeInIncomeTaxReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in income tax reserves (including interest)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationChangeInIncomeTaxReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Change In Income Tax Reserves</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationChangeInIncomeTaxReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax rate reconciliation change in income tax reserves.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RatioOfIndebtednessToNetCapital1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leverage ratio</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred income taxes</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfFacilitiesYetToClose_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of facilities yet to close.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PatentsTrademarksTradeNamesAndOtherMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Patents, Trademarks, Trade Names and Other [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PatentsTrademarksTradeNamesAndOtherMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Patents trademarks trade names and other.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrualClassifiedCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term product warranties</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Property, Plant and Equipment</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue from Contracts with Customers</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockholdersEquityTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders Equity [Table]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockholdersEquityTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stockholders Equity [Table]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Cash and cash equivalents at beginning of period</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuriborRateFloorMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">EURIBOR rate floor member.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationExecutiveCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax rate reconciliation executive compensation.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Axis]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Stock-based compensation</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ExpenseOfRestructuringActivitiesAndOtherTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring and Other</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ExpenseOfRestructuringActivitiesAndOtherTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Expense of restructuring activities and other.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignExchangeOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives Foreign Currency Options [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignExchangeOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Exchange Option [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discount rate</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Disclosure [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected annual dividends per share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Per Share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award fair value assumptions expected dividend per share.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfForeignExchangeContractsStatementOfFinancialPositionTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Foreign Currency Option Contracts Purchased to Hedge Conversion</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredTaxLiabilitiesDepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax liabilities depreciation and amortization.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value of MKS shares issued</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementFiveMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement Five [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrualPeriodIncreaseDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Standard and Extended Product Warranty Accrual, Period Increase (Decrease), Total</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorName_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Auditor Name</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total purchase price, net of cash and cash equivalents acquired</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total purchase price, net of cash and cash equivalents acquired</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_StatementScenarioAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scenario</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AtotechMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Atotech [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AtotechMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Atotech member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InlandRevenueSingaporeIRASMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inland Revenue, Singapore (IRAS) [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonLaserProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Laser Products [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonLaserProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non Laser Products [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_WarrantyPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warranty period.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Benchmark</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Benchmark [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Filer Category</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Filer Category</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reconciliation of Assets from Segment to Consolidated [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermSofrRatePlusApplicableCreditSpreadAdjustmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term SOFR Rate (Plus Applicable Credit Spread Adjustment) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermSofrRatePlusApplicableCreditSpreadAdjustmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term SOFR Rate (Plus Applicable Credit Spread Adjustment) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermSofrRatePlusApplicableCreditSpreadAdjustmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term SOFR rate (plus applicable credit spread adjustment) member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementSixMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement Six [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementSixMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Swap Agreement Six.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfBusinessCombinationAcquireeNetRevenuesAndNetEarningsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Business Combination Acquiree Net Revenues And Net Earnings Table [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfBusinessCombinationAcquireeNetRevenuesAndNetEarningsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of business combination acquire net revenues and net earnings table text block.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">New Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">New Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">New term loan facility.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other comprehensive income (loss)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, plant and equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Current Reporting Status</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ForeignInterestCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Foreign interest carryforwards.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Asset Class</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Class [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Inventory</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Inventories</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventories</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfRestructuringAndOtherCostTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Restructuring And Other Cost [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfRestructuringAndOtherCostTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of restructuring and other cost.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Documents Incorporated by Reference</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Documents Incorporated by Reference [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DevelopedTechnologyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Developed Technology [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DevelopedTechnologyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Developed technology.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross Unrealized Gains and (Losses) Aggregated by Investment Category</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Tax Identification Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Tax Identification Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Location</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Location [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, no par value, 200 shares authorized; 66.6 and 55.5 shares issued and outstanding at December 31, 2022 and 2021, respectively</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Value, Issued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidation Items</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermLoansUnderNewTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term Loans under New Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermLoansUnderNewTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term Loans under New Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermLoansUnderNewTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term loans under new term loan facility member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Retained Earnings (Accumulated Deficit), Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retained earnings</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings (Accumulated Deficit)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockAppreciationRightsSARSMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock Appreciation Rights (SARs) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockAppreciationRightsSARSMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Appreciation Rights (SARs) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Components</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Components [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net gain (loss) recognized in accumulated OCI</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Derivative, Gain (Loss) on Derivative, Net, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative, Gain (Loss) on Derivative, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Original Issue Discount [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Original Issue Discount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Original Issue Discount [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OriginalIssueDiscountMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Original issue discount.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition and integration costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Acquisition Related Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduledQuarterlyPaymentsPercentageOfOriginalPrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scheduled quarterly payments percentage of original principal amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduledQuarterlyPaymentsPercentageOfOriginalPrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scheduled Quarterly Payments Percentage of Original Principal Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduledQuarterlyPaymentsPercentageOfOriginalPrincipalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Scheduled quarterly payments percentage of original principal amount.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounting Standards Update</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Standards Update [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ProceedsFromPaymentsForEmployeeStockAwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net payments related to employee stock awards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ProceedsFromPaymentsForEmployeeStockAwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Payments For Employee Stock Awards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ProceedsFromPaymentsForEmployeeStockAwards_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from payments for employee stock awards.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaximumPercentageOfPayrollForPurchaseOfStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of Common Stock through payroll deductions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaximumPercentageOfPayrollForPurchaseOfStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum Percentage Of Payroll For Purchase Of Stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaximumPercentageOfPayrollForPurchaseOfStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Maximum percentage of payroll for purchase of stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumAgeLimitForSpecifiedAdditionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum age limit for specified additional amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumAgeLimitForSpecifiedAdditionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum Age Limit For Specified Additional Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumAgeLimitForSpecifiedAdditionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Minimum age limit for specified additional amount.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred financing fees and original issue discount fees</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Issuance Costs, Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyLiabilityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product Warranty Liability [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyLiabilityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product Warranty Liability [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeasesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Leases [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Contract with Customer, Liability, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance, January 1</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance, December 31</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Liability</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerRelationshipsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer Relationships [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerRelationshipsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Relationships [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disaggregation Of Revenue [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disaggregation of Revenue [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PriorTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prior Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PriorTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prior Term Loan Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PriorTermLoanFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prior term loan facility.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAndIntangibleAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill And Intangible Assets [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAndIntangibleAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill And Intangible Assets [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAndIntangibleAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Goodwill and intangible assets.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Expected Future Benefit Payment, Year Three</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Emerging Growth Company</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Emerging Growth Company</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfIntangibleAssetIndefiniteLivedExcludingGoodwillStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment, Intangible Asset, Indefinite-Lived (Excluding Goodwill), Statement of Income or Comprehensive Income [Extensible Enumeration]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Business Acquisitions By Acquisition [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Business Acquisitions, by Acquisition [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitContributions_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Payment for Pension and Other Postretirement Benefits, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitContributions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Company's contributions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitContributions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payment for Pension and Other Postretirement Benefits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Interest cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest cost on projected benefit obligations</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Interest Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in plan assets:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United States</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Federal Tax Expense (Benefit)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DebtIssuanceCostsAmortizationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt issuance costs, amortization period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DebtIssuanceCostsAmortizationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt issuance costs, amortization period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DebtIssuanceCostsAmortizationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt issuance costs, amortization period.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividend declared, shareholders of record date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Dividends Payable, Date of Record</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maturities of investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetirementPlanTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retirement Plan Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetirementPlanTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Plan Type [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MaximumRemainingMaturityOfForeignCurrencyDerivatives1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum period for hedging a portion of forecasted foreign currency denominated intercompany sales of inventory</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MaximumRemainingMaturityOfForeignCurrencyDerivatives1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum Remaining Maturity of Foreign Currency Derivatives</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanAssetCategoriesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined Benefit Plan, Plan Assets, Category</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanAssetCategoriesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Plan Assets, Category [Domain]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_EuropeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Europe [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_EuropeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Europe [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanServiceCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Service cost</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Voluntary Filers</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Voluntary Filers</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationAndRetirementDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Benefits [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation and amortization</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation, Depletion and Amortization, Nonproduction</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Transition Report</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Transition Report</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Fair Value Disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense)</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AccountsReceivableAllowancesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable Allowances Policy [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AccountsReceivableAllowancesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accounts receivable allowances.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Segment Reporting Information By Segment [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and Contingencies</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationCompensationExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination compensation expenses.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Foreign</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated other comprehensive income (loss)</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Other Comprehensive Income (Loss), Net of Tax</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade accounts receivable, net of allowance for doubtful accounts of $11 and $4 at December 31, 2022 and 2021, respectively</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Accounts Receivable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts Receivable, after Allowance for Credit Loss, Current, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, after Allowance for Credit Loss, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Common Stock, Shares Outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock, Shares Outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GroupInsuranceContractsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Group Insurance Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GroupInsuranceContractsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Group Insurance Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GroupInsuranceContractsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Group Insurance Contracts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GroupInsuranceContractsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Group insurance contracts.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Year5Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Year 5 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Year5Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Year 5 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Year5Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Year 5 member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AdjustmentsRecordedToCorrectOverstatementOfNonCurrentDeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Adjustments recorded to correct overstatement of non-current deferred tax liabilities</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss) Attributable to Parent</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Income Taxes Disclosure Abstract.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementInputsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Measurements</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherNonCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other assets</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherNonCurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other non current assets fair value disclosure.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise Price Range</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Unrecognized pension gain (loss)</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MaximumPeriodOfCompanysResearchAndDevelopmentProjects_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Maximum period of company's research and development projects.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USGovernmentAgenciesDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Agency Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USGovernmentAgenciesDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">US Government Agencies Debt Securities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ChangeInContractWithCustomerLiabilityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in Contract with Customer, Liability [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ChangeInContractWithCustomerLiabilityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change In Contract With Customer Liability [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ChangeInContractWithCustomerLiabilityLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change in Contract with Customer, Liability [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Payment Arrangement, Noncash Expense, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Noncash Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property, plant and equipment, net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, plant and equipment, net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesFromAcquisition_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">RSUs issued in Atotech Acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesFromAcquisition_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Shares From Acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesFromAcquisition_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award equity instruments other than options shares from acquisition.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BankersAcceptanceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Bankers' Acceptance Drafts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BankersAcceptanceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Bankers Acceptance [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Award Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Award Type [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net issuance under stock-based plans</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LineOfCreditFacilityRenewalPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate borrowings expire and renewal period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LineOfCreditFacilityRenewalPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Renewal Period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LineOfCreditFacilityRenewalPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Line Of Credit Facility Renewal Period.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additions Charged to Other Accounts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Other Account</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForNinetyPercentOfRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of customers accounted for greater than 90 % of net revenue</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForNinetyPercentOfRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Customers Accounted For Ninety Percent Of Revenue</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NumberOfCustomersAccountedForNinetyPercentOfRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of customers accounted for ninety percent of revenue</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of 12(b) Security</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Title of 12(b) Security</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Intangible assets, not subject to amortization</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finite-Lived Intangible Assets, Gross, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible assets, Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Income Taxes [Line Items].</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current taxes:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Income Tax Expense (Benefit), Continuing Operations [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TaxProvisionRelatedToHistoricalOutsideBasisDifferences_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax provision related to historical outside basis differences</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TaxProvisionRelatedToHistoricalOutsideBasisDifferences_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax provision related to historical outside basis differences</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TaxProvisionRelatedToHistoricalOutsideBasisDifferences_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tax provision related to historical outside basis differences.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition, Pro Forma Information [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeNotionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notional Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeNotionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Notional amount in EUR/USD</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeNotionalAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative, Notional Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from operating activities:</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Component</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Component [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Debt Securities, Available-for-Sale</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyLiabilityTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product Warranty Liability [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyLiabilityTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product Warranty Liability [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Settlement of share-based awards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Accelerated Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarEuroMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Dollar/euro [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarEuroMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">U S Dollar Euro [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarEuroMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">U S Dollar Euro [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net revenues</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: imputed interest</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_StatementGeographicalAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographical</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Unaudited Pro Forma Financial Information</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Security Exchange Name</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OtherNonCurrentLiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other non current liabilities fair value disclosure.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total purchase price, net of cash and cash equivalents acquired</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Future Lease Payment Under Non-Cancelable Lease</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CompletedTechnologyRightsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Completed Technology [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UKPoundSterlingEuroMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">U K Pound Sterling Euro.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AmortizationOfInventoryOnStepUpBasisAdjustmentToFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of inventory step-up adjustment to fair value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AmortizationOfInventoryOnStepUpBasisAdjustmentToFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization Of Inventory On Step Up Basis Adjustment To Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AmortizationOfInventoryOnStepUpBasisAdjustmentToFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amortization of inventory on step up basis adjustment to fair value.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Disclosure [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CashAndCashEquivalentsAndInvestmentsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and Cash Equivalents and Investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CashAndCashEquivalentsAndInvestmentsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash And Cash Equivalents And Investments Policy [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CashAndCashEquivalentsAndInvestmentsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash and cash equivalents and investments.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Significant Other Observable Inputs (Level 2) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 2 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from investing activities:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Investing Activities [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated Net Amortization Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increases for tax positions taken during the current year</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and contingencies (Note 22)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeAndHedgingTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative And Hedging [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeAndHedgingTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative And Hedging [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeAndHedgingTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Derivative And Hedging [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Authority, Name [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares issued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Issued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessAcquisitionDateOfCompletion_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Date of completed previously announced acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessAcquisitionDateOfCompletion_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Date Of Completion</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessAcquisitionDateOfCompletion_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business acquisition date of completion.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income taxes payable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments and Hedging Activities Disclosure [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ContractWithCustomerLiabilityAdditions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additions to deferred revenue and customer advances</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ContractWithCustomerLiabilityAdditions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability Additions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ContractWithCustomerLiabilityAdditions_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract with customer liability additions.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USTreasurySecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Treasury Obligations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USTreasurySecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">US Treasury Securities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable Rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Variable Rate [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedContributionPlanMinimumAnnualContributionsPerEmployeePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee contribution to Company's profit sharing plan percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedContributionPlanMinimumAnnualContributionsPerEmployeePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Minimum Annual Contributions Per Employee Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedContributionPlanMinimumAnnualContributionsPerEmployeePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined Contribution Plan Minimum Annual Contributions Per Employee Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Company's Restructuring Activity</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring and Related Costs [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Tax Authority, Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Authority, Name [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="country_CN_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">China [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="country_CN_lbl" xlink:role="http://www.xbrl.org/2003/role/label">CHINA</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Investment1Axis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment1</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Investment1Axis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment1 [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAndIntangibleAssetsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill And Intangible Assets [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAndIntangibleAssetsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill And Intangible Assets [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillAndIntangibleAssetsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Goodwill and intangible assets.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Primary Net Hedging Positions and Corresponding Fair Values</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segments [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Global intangible low taxed income, net of foreign tax credits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Leases [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromBankDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from borrowing, net of deferred financing fees paid</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromBankDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Bank Debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounting Standards Update</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax Credit Carryforward</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax Credit Carryforward [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherRestructuringCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other restructuring charges, facility cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherRestructuringCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Restructuring Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfSignificantAccountingPoliciesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Significant Accounting Policies [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfSignificantAccountingPoliciesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Significant Accounting Policies [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfSignificantAccountingPoliciesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of significant accounting policies [Table].</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders&#8217; equity:</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State income taxes, net of credits and net of federal benefit</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Available For Sale Securities [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Available-for-Sale Securities [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherIntangibleAssetsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Intangible Assets [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LineOfCreditFacilityMinimumAdditionalBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility minimum additional borrowing capacity</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LineOfCreditFacilityMinimumAdditionalBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Minimum Additional Borrowing Capacity</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LineOfCreditFacilityMinimumAdditionalBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Line of credit facility minimum additional borrowing capacity.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segments [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LevelOfPerformanceTargetAchievedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level of performance target achieved</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LevelOfPerformanceTargetAchievedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Level Of Performance Target Achieved Percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LevelOfPerformanceTargetAchievedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Level of performance target achieved percentage.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on plan assets</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Exchange</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PaymentsAndAdjustmentForRestructuring_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments and adjustments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PaymentsAndAdjustmentForRestructuring_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments And Adjustment For Restructuring</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PaymentsAndAdjustmentForRestructuring_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments and adjustment for restructuring.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Products [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of intangible assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of Intangible Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AwardTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Award Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AwardTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Award Type [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Standard and Extended Product Warranty Accrual, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Standard and Extended Product Warranty Accrual</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Noncash Income (Expense), Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Noncash Income (Expense)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Event [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total compensation expense related to restricted stock unites</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income before income taxes:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred tax assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of Long-Lived Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Nonoperating Income (Expense), Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other expense, net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Nonoperating Income (Expense)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MaturitiesOfLongTermDebtAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maturities of Long-Term Debt [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments Not Designated as Hedging Instruments [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllocatedShareBasedCompensationEffectOnEarningPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllocatedShareBasedCompensationEffectOnEarningPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Allocated Share Based Compensation Effect On Earning Per Share Basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AllocatedShareBasedCompensationEffectOnEarningPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Allocated share based compensation effect on earning per share basic.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Expected Future Benefit Payment, Year Two</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Foreign Currency Translation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Foreign Currency Translation Gain (Loss)</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Schedule of Estimated Fair Value and Carrying Value of Company's Debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Research and Development Expense, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease payments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermSofrBorrowingsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term SOFR Borrowings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermSofrBorrowingsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term SOFR Borrowings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermSofrBorrowingsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term SOFR borrowings member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Central Index Key</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Central Index Key</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Advertising Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Advertising Cost [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in valuation allowance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finite-Lived Intangible Assets [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Short-Term Investments, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Numerator:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss) Attributable to Parent [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ROU assets obtained in exchange for new lease liabilities, Finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Right-of-Use Asset Obtained in Exchange for Finance Lease Liability</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MajorCustomersAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MajorCustomersAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BenefitOfTheTaxIncentive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Benefit of the tax incentive</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BenefitOfTheTaxIncentive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Benefit Of The Tax Incentive</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BenefitOfTheTaxIncentive_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Benefit of the tax incentive.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Policies [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearSixToTen_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028-2032</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearSixToTen_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Expected Future Benefit Payments Year Six To Ten</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearSixToTen_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan expected future benefit payments year six to ten.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments, Debt and Equity Securities [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Redemption, Period [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Available-for-sale Securities [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disaggregation of Revenue [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disaggregation of Revenue [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Right-of-Use Asset, after Accumulated Amortization</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finance Lease, Right-of-Use Asset, after Accumulated Amortization, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TwoThousandFourteenEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2014 ESPP [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TwoThousandFourteenEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Fourteen Employee Stock Purchase Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TwoThousandFourteenEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand fourteen employee stock purchase plan</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Swap Agreement Two [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement Two [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Swap agreement two.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: accumulated depreciation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Property Plant And Equipment [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected volatility</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OperatingLossCarryforwardsExpiringTwoThousandThirtyNineMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2039 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OperatingLossCarryforwardsExpiringTwoThousandThirtyNineMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards Expiring Two Thousand Thirty Nine [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OperatingLossCarryforwardsExpiringTwoThousandThirtyNineMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Operating loss carryforwards expiring two thousand thirty nine.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average discount rate-finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Weighted Average Discount Rate, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Investment1Domain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment1</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_Investment1Domain_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Investment1.</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Frequency</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Frequency [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidation Items</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares available for future grant</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-Based Compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Amortization of Debt Issuance Costs and Discounts, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of debt issuance costs and original issue discount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of Debt Issuance Costs and Discounts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financing cash flows used for finance leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Principal Payments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestructuringCostAndOtherCostLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Cost and Other Cost [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestructuringCostAndOtherCostLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Cost And Other Cost [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestructuringCostAndOtherCostLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Restructuring cost and other cost.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InterestRateHedgeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Rate Hedge [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InterestRateHedgeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Hedge [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InterestRateHedgeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest rate hedge.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioForecastMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forecast [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioForecastMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Forecast [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="country_KR_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">South Korea [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="country_KR_lbl" xlink:role="http://www.xbrl.org/2003/role/label">KOREA, REPUBLIC OF</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease, Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeLiabilitiesAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives - interest rate hedge - non-current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeLiabilitiesAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Current Interest Rate Fair Value Hedge Liabilities At Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NonCurrentInterestRateFairValueHedgeLiabilitiesAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non- current interest rate fair value hedge liabilities at fair value.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ROU assets obtained in exchange for new lease liabilities, Operating leases</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Right-of-Use Asset Obtained in Exchange for Operating Lease Liability</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Fair value realized loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) on Foreign Currency Fair Value Hedge Derivatives</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerAdvancesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer Advances [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerAdvancesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Advances [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CustomerAdvancesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer Advances [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Adjustments to reconcile net income to net cash provided by operating activities:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule II - Valuation and Qualifying Accounts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retained Earnings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AcquisitionDateLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition Date [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AcquisitionDateLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Acquisition Date [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AcquisitionDateLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Acquisition Date [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax Credit Carryforward, Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax Credit Carryforward, Name [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate number of common stock issued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition, Equity Interest Issued or Issuable, Number of Shares</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_NameOfMajorCustomerDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_NameOfMajorCustomerDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Money Market Funds [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Money Market Funds [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Currency translation adjustments</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAssetsForPlanBenefitsPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined benefit plan assets, percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAssetsForPlanBenefitsPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Assets For Plan Benefits Percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAssetsForPlanBenefitsPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined Benefit Plan Assets For Plan Benefits Percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments, Estimated Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale and Held-to-Maturity, Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gain (Loss) on Disposition of Property Plant Equipment, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Gain on sale of long-lived assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) on Disposition of Property Plant Equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ContractWithCustomerAmountOfDeferredRevenueAndCustomerAdvancesRecognized_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Amount of deferred revenue and customer advances recognized in income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ContractWithCustomerAmountOfDeferredRevenueAndCustomerAdvancesRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Amount Of Deferred Revenue And Customer Advances Recognized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ContractWithCustomerAmountOfDeferredRevenueAndCustomerAdvancesRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract with customer amount of deferred revenue and customer advances recognized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FederalHomeLoanBanksAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Federal Home Loan Banks [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Property, Plant and Equipment, Gross, Ending Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Property, Plant and Equipment, Gross, Beginning Balance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property, Plant and Equipment, Gross, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, plant and equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquired goodwill, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill, Acquired During Period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinitelivedIntangibleAssetsAcquired1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquired intangible assets, purchase price</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinitelivedIntangibleAssetsAcquired1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets Acquired</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting percentage per year of RSUs from date of grant</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Interactive Data Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Interactive Data Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross tax research other tax credit carryforwards</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax Credit Carryforward, Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityPublicFloat_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Public Float</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityPublicFloat_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Public Float</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsDollarUkPoundMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Dollar/U.K. Pound Sterling [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsDollarUkPoundMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Us Dollar Uk Pound [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsDollarUkPoundMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">US Dollar UK Pound [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred financing fees, original issuance discount and re-pricing fee</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Debt issuance costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Debt Issuance Costs, Noncurrent, Net, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Issuance Costs, Noncurrent, Net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Assets Fair Value Disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CurrentAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Current assets fair value disclosure.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfSignificantAccountingPoliciesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Significant Accounting Policies [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfSignificantAccountingPoliciesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Significant Accounting Policies [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfSignificantAccountingPoliciesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of significant accounting policies [Line Items].</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationForeignDerivedIntangibleIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign derived intangible income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationForeignDerivedIntangibleIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Foreign Derived Intangible Income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EffectiveIncomeTaxRateReconciliationForeignDerivedIntangibleIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax rate reconciliation foreign derived intangible income.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected long-term rate of return on assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesTableTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes Table [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesTableTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes Table [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_IncomeTaxesTableTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Income Taxes [Table].</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">2021 lease payment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year One</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OneCustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">One Customer [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OneCustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">One Customer [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OneCustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">One customer.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewportCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Newport Corporation [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewportCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Newport Corporation [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewportCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Newport Corporation [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_NewportCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Newport Corporation.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Weighted Average Rates Used to Determine Net Periodic Benefit Costs</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Assumptions [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPercentageOfEarningsBeforeInterestTaxesDepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum percentage of consolidated EBITDA</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPercentageOfEarningsBeforeInterestTaxesDepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum Percentage Of Earnings Before Interest Taxes Depreciation And Amortization</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPercentageOfEarningsBeforeInterestTaxesDepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Minimum percentage of earnings before interest taxes depreciation and amortization.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EmployeePerformanceAwardBonusExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Bonus expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EmployeePerformanceAwardBonusExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee Performance Award Bonus Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EmployeePerformanceAwardBonusExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Employee bonus expense (includes bonus expense and performance awards).</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseholdImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leasehold Improvements [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseholdImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Leasehold Improvements [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred taxes:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Local Phone Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. federal statutory tax rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Balance at beginning of year</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance at end of year</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenues from External Customers and Long-Lived Assets [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenues from External Customers and Long-Lived Assets [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Estimated Fair Value of Assets Acquired and Liabilities Assumed</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Computation of Basic and Diluted Net Income Per Share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockExercisePriceAsPercentageOfClosingMarketPrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of closing price of the Common Stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockExercisePriceAsPercentageOfClosingMarketPrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Exercise Price As Percentage Of Closing Market Price</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_StockExercisePriceAsPercentageOfClosingMarketPrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock exercise price as percentage of closing market price.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermBorrowingsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Debt [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Projected benefit obligations, beginning of year</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Projected benefit obligations, end of year</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Benefit Obligation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Disclosure [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Revenue [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Revenue [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share Based Compensation Arrangement By Share Based Payment Award [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanPensionPlanChangeInBenefitObligationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in projected benefit obligations:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanPensionPlanChangeInBenefitObligationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Pension Plan Change In Benefit Obligation [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanPensionPlanChangeInBenefitObligationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined Benefit Plan Pension Plan Change In Benefit Obligation [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateSwapMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Interest Rate Swaps [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateSwapMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Rate Hedge [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateSwapMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Swap [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SummaryOfIncomeTaxContingenciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits, Excluding Interest and Penalties</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SummaryOfIncomeTaxContingenciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Summary of Income Tax Contingencies [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Revenue from Contracts with Customers</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disaggregation of Revenue [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Available-for-sale securities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Investments, Cost</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale and Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other non-current liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Expected Future Benefit Payment, Year Five</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComponentsOfDeferredTaxLiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax liabilities:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComponentsOfDeferredTaxLiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Components of Deferred Tax Liabilities [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Liability, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Location</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Location [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ForeignCurrencyTranslationAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Currency Translation, Accumulated Impairment Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ForeignCurrencyTranslationAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign currency translation, accumulated impairment loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ForeignCurrencyTranslationAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Foreign currency translation, accumulated impairment loss.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BorrowingsUnderNewRevolvingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Borrowings under New Revolving Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BorrowingsUnderNewRevolvingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Borrowings under New Revolving Facility [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BorrowingsUnderNewRevolvingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Borrowings under new revolving facility member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year One</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities assumed</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Selling, General and Administrative [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Selling, General and Administrative Expenses [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ZeroCustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Zero Customer [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ZeroCustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Zero Customer [member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ZeroCustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Zero customer.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SARs outstanding</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">RSUs, beginning of period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">RSUs end of period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherOperatingIncomeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Expense, Net [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherOperatingIncomeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Operating Income (Expense) [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-Term Debt, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Long term debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term debt, net</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfAllocationOfPurchasePriceTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Purchase Price</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfAllocationOfPurchasePriceTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Allocation Of Purchase Price Table [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ScheduleOfAllocationOfPurchasePriceTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of allocation of purchase price.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory Disclosure [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer Concentration Risk [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Concentration Risk [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument, Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Name [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_LeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Present value of lessee's discounted obligation for lease payments from operating and financing lease, classified as current.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Year Focus</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Year Focus</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued interest on unrecognized tax benefits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PercentageOfPayrollDeductionToCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of payroll deduction to compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PercentageOfPayrollDeductionToCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Payroll Deduction To Compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PercentageOfPayrollDeductionToCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of payroll deduction to compensation.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finished goods</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Finished Goods, Net of Reserves</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FinanceLease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FinanceLease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FinanceLease_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Finance lease.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repayment of Atotech debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfDebt_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments of short and long-term borrowings</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Repayments of Debt</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Two</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndOtherIncome_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Interest income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndOtherIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndOtherIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest and Other Income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives-foreign exchange forward contracts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Currency Cash Flow Hedge Asset at Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Basic, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxesPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income taxes</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxesPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes Paid</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash dividend, per common share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Dividends, Per Share, Declared</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationAndEmployeeBenefitPlansTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Benefit Plans</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationAndEmployeeBenefitPlansTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Compensation and Employee Benefit Plans [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredCompensationPlanAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred compensation plan assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredCompensationPlanAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Compensation Plan Assets Fair Value Disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DeferredCompensationPlanAssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Compensation Plan Assets Fair Value Disclosure</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsCommonStockCash_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cash dividend</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsCommonStockCash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Dividends, Common Stock, Cash</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillGross_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance, Goodwill Gross Carrying Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillGross_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance, Goodwill Gross Carrying Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill, Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ASSETS</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PercentageOfAggregateAmountOfAllCommitments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of aggregate amount of all commitments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PercentageOfAggregateAmountOfAllCommitments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage of Aggregate Amount of all Commitments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PercentageOfAggregateAmountOfAllCommitments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of aggregate amount of all commitments.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ElectroScientificIndustriesIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Electro Scientific Industries Inc [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ElectroScientificIndustriesIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Electro Scientific Industries Inc [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_ElectroScientificIndustriesIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Electro Scientific Industries, Inc.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GrossProfit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gross profit</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GrossProfit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross profit</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GrossProfit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gross Profit</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanEquitySecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Securities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanEquitySecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Equity Securities [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GuaranteesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Guarantees [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Outstanding principal amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Senior secured credit facility</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Secured term loan, face amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Purchase Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock Purchase Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Employee stock purchase plan [member].</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Unclassified [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestructuringAndOtherCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring and other</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestructuringAndOtherCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring And Other Charges</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestructuringAndOtherCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents Restructuring and Other Charges.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ChangeInContractWithCustomerLiabilityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change in Contract with Customer, Liability [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Lived Tangible Asset [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Benchmark</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Benchmark [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">LIABILITIES AND STOCKHOLDERS&#8217; EQUITY</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LandMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Land [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LandMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Land [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase commitments covered by aggregate value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Commitment, Remaining Minimum Amount Committed</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPayableAmountPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash dividend to be paid</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPayableAmountPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Dividends Payable, Amount Per Share</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermLoanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term Loan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermLoanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term Loan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TermLoanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term loan.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Various Interest Rate Hedges</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Interest Rate Derivatives [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Policy [Policy Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities, Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities, Name [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign exchange forward contracts</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Currency Cash Flow Hedge Liability at Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Tax Authority</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Authority [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableTrade_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableTrade_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Payable, Trade</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossUnrealized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrealized gain net of premium</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossUnrealized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Currency Transaction Gain (Loss), Unrealized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Expected Amortization, Year Four</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares authorized for issuance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Compensation Arrangement with Individual, Shares Authorized for Issuance</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reporting unit, percentage of fair value in excess of carrying amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Expected Amortization, Year Two</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Segment, Geographic Area, Product Information and Significant Customer Information</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting Disclosure [Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanCashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanCashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Cash [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Significant Components of Deferred Tax Assets and Deferred Tax Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Goodwill [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Hierarchy and NAV</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityStatementOfFinancialPositionExtensibleList_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarChineseRenminbiMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Dollar/Chinese Renminbi [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarChineseRenminbiMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">U S Dollar /Chinese Renminbi [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_USDollarChineseRenminbiMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">U S Dollar /Chinese renminbi.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryWriteDown_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Inventory related excess and obsolete charges</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryWriteDown_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Provision for excess and obsolete inventory</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryWriteDown_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory Write-down</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net unrecognized tax benefits, excluding interest and penalties, related to foreign tax positions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPercentageOfRecognizedTaxBenefitsFromUncertainTaxPosition_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum percentage of recognition of tax benefits from uncertain tax positions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPercentageOfRecognizedTaxBenefitsFromUncertainTaxPosition_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum Percentage Of Recognized Tax Benefits From Uncertain Tax Position</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_MinimumPercentageOfRecognizedTaxBenefitsFromUncertainTaxPosition_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Minimum percentage of recognized tax benefits from uncertain tax position.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Frequency</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Frequency [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in operating assets and liabilities, net of businesses acquired:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Operating Capital [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net effect on net income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net effect on net income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expense, after Tax</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsdTrancheAMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">USD Tranche A [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsdTrancheAMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">USD Tranche A [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UsdTrancheAMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">USD tranche A member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease cost:</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease, Cost [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllowanceForCreditLossMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation Allowance for Doubtful Accounts [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllowanceForCreditLossMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Allowance, Credit Loss [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateCapMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Rate Caps [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestRateCapMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Cap [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United States</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Domestic</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Company contributions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Plan Assets, Contributions by Employer</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cover [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EarningsPerShareLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Earnings Per Share [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EarningsPerShareLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EarningsPerShareLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Earnings Per Share [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration risk, percentage</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_InsuranceReimbursementReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Insurance reimbursement received.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingChangesAndErrorCorrectionsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Changes and Error Corrections [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SemiconductorProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Semiconductor Products [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SemiconductorProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Semiconductor products [Member].</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Swap Agreement One [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SwapAgreementOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swap Agreement One [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossRealized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net foreign exchange losses from re-measurement</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillTranslationAdjustmentsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign currency translation, Gross Carrying Amount</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillTranslationAdjustmentsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill Translation Adjustments Gross</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_GoodwillTranslationAdjustmentsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Goodwill translation adjustments gross.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfRevenueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of revenues:</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedGain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments, Gross Unrealized Gains</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedGain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale and Held-to-Maturity, Cumulative Unrecognized Gain</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FederalStateAndForeignMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Federal, State and Foreign [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FederalStateAndForeignMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Federal State And Foreign [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_FederalStateAndForeignMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Federal state and foreign.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_CashPaidDuringPeriodForInterestAndIncomeTaxAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash paid during the period for:</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current liabilities:</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividend paid date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Dividends Payable, Date to be Paid</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Defined Benefit Plan Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Defined Benefit Plans Disclosures [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationShareReceivedPerCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares received per common shares</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationShareReceivedPerCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Share Received Per Common Stock</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationShareReceivedPerCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination share received per common stock.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pre-Tax Effect Within Consolidated Statements of Operations of Recording Stock-Based Compensation</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UnderstatementOfAccumulatedOtherComprehensiveIncomeAndOtherComprehensiveIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Understatement of accumulated other comprehensive income and other comprehensive income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UnderstatementOfAccumulatedOtherComprehensiveIncomeAndOtherComprehensiveIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Understatement of Accumulated Other Comprehensive Income and Other Comprehensive Income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_UnderstatementOfAccumulatedOtherComprehensiveIncomeAndOtherComprehensiveIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Understatement of accumulated other comprehensive income and other comprehensive income.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentsGainLossLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Instruments, Gain (Loss) [Line Items]</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_SummaryOfWeightedAverageRemainingTermsForAllLeasesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Weighted Average Remaining Terms for All Leases</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in investing activities</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductWarrantyAccrualAdditionsFromBusinessAcquisition_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assumed product warranty liability from Atotech Acquisition</link:label>
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    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Expected Amortization, Year Five</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AcquiredGoodwillAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Acquired goodwill, Accumulated Impairment Loss</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_AcquiredGoodwillAccumulatedImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Acquired goodwill, accumulated impairment loss.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestrictedStockUnitsGrantedToDirectorsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">RSUs Granted To Directors [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestrictedStockUnitsGrantedToDirectorsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock Units Granted To Directors [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_RestrictedStockUnitsGrantedToDirectorsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">RSU granted to directors.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-Term Investments, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Investments</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities assumed through Atotech Acquisition</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan, Benefit Obligation, Business Combination</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MaterialReconcilingItemsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment Reconciling Items [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MaterialReconcilingItemsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reconciling Items [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated useful lives</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Useful Life</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Effective Income Tax Rate Reconciliation, Tax Credit, Percent, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Federal tax credits</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Tax Credit, Percent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Expected Amortization, Year Three</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares authorized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares Authorized</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroChineseRenminbiMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Euro Chinese Renminbi [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_EuroChineseRenminbiMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Euro Chinese Renminbi.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Expense [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Expense [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trading Symbol</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trading Symbol</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TopTenCustomersMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Top Ten Customers [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TopTenCustomersMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Top Ten Customers [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_TopTenCustomersMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Top ten customers.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BorrowingsUnderEuroTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Borrowings under Euro Tranche B [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BorrowingsUnderEuroTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Borrowings under Euro Tranche B [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BorrowingsUnderEuroTrancheBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Borrowings under Euro Tranche B member.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Photon Control, Inc. [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Photon Control Inc [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Photon Control Inc [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_PhotonControlIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Photon Control Inc.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Selling, General and Administrative Expense, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Selling, general and administrative</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Selling, General and Administrative Expense</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ValuationAndQualifyingAccountsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Event Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Other</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OperatingLossCarryforwardsExpiringTwoThousandSeventeenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OperatingLossCarryforwardsExpiringTwoThousandSeventeenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards Expiring Two Thousand Seventeen [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_OperatingLossCarryforwardsExpiringTwoThousandSeventeenMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Operating loss carryforwards expiring two thousand seventeen.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, interest rate terms</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Interest Rate Terms</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Balance Sheet Location [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total comprehensive income</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Comprehensive Income (Loss), Net of Tax, Attributable to Parent</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Risk-free interest rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of long-lived assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds from Sale of Property, Plant, and Equipment, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Sale of Property, Plant, and Equipment</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts Payable, Current, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Current</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Foreign withholding taxes</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Undistributed Foreign Earnings</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Other Operating Assets, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other current and non-current assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Operating Assets</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Axis]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeEffectiveDates_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effective Date</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeEffectiveDates_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Effective Dates</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DerivativeEffectiveDates_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Derivative effective dates.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashFlowHedgingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Flow Hedging [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashFlowHedgingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Flow Hedging [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Type [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Lived Tangible Asset [Domain]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationPricePerShareOfCommonStockInCash_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Price per share of common stock in cash</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationPricePerShareOfCommonStockInCash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Price Per Share Of Common Stock In Cash</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_BusinessCombinationPricePerShareOfCommonStockInCash_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination, price per share of common stock in cash.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAssetsForPlanBenefitsGuaranteedRateOfReturn_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined benefit plan assets guaranteed rate of return</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAssetsForPlanBenefitsGuaranteedRateOfReturn_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Defined Benefit Plan Assets For Plan Benefits Guaranteed Rate Of Return</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mksi_DefinedBenefitPlanAssetsForPlanBenefitsGuaranteedRateOfReturn_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Defined benefit plan assets for plan benefits guaranteed rate of return.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Net Revenues by Major Customers</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedules of Concentration of Risk, by Risk Factor [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ChangesInProjectedBenefitObligationsFairValueOfPlanAssetsAndFundedStatusOfPlanTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Changes in Projected Benefit Obligations and Plan Assets, and Ending Balances of Defined Benefit Plans</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ChangesInProjectedBenefitObligationsFairValueOfPlanAssetsAndFundedStatusOfPlanTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan [Table Text Block]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Well-known Seasoned Issuer</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Well-known Seasoned Issuer</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued for Atotech Acquisition, Shares</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Acquisitions</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Employee-related Liabilities, Total</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-current accrued compensation</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee-related Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, value of shares authorized to repurchase</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchaseProgramAuthorizedAmount1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Repurchase Program, Authorized Amount</link:label>
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