SEC Form 5

FORM 5		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0362 Estimated average burden hours per response: 1.0
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
	Form 3 Holdings Reported.
X	Form 4 Transactions Reported.

1. Name and Address of Reporting Person* BERLINGHIERI LEO (Last) (First) (Middle) 2 TECH DRIVE (Street) ANDOVER MA 01810 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol MKS INSTRUMENTS INC [ MKSI ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner X Officer (give title below) Other (specify below) President and CEO
	3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year) 12/31/2009
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)	4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned at end of Issuer's Fiscal Year (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
				Amount	(A) or (D)	Price
Common Stock	11/24/2009		J4(1)	6,724	D	$0	50,693	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)	5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
					(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Unit	(2)	11/23/2009		4J(1)		2,761	(3)	(3)	Common Stock	2,761	$0	81,607	D
Restricted Stock Unit	(2)	03/16/2009		4A	7,308(4)		(5)	(5)	Common Stock	7,308	$0	88,915	D

Explanation of Responses:

1. These shares were transferred prusuant to DRO.

2. Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

3. One half of RSUs shall vest in equal annual installments over three years, and the other half shall be subject to the achievement of performance criteria, and thereafter shall vest in equal annual installments over three years.

4. These shares were inadvertently not reported with the equity filed on March 16, 2009.

5. These shares are subject to the achievement of performance criteria and thereafter vests in equal installments over three years

	/s/Renee M. Donlan POA	02/12/2010
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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