MKS Instruments Announces Fourth Quarter 2006 Conference Call

WILMINGTON, Mass., Jan. 19 /PRNewswire-FirstCall/ -- MKS Instruments, Inc. (Nasdaq: MKSI), a leading worldwide provider of process control technologies for improving productivity in semiconductor and other advanced manufacturing processes, today announced that it will release fourth quarter and full year 2006 financial results prior to the opening of the market on Thursday, February 15, 2007. A conference call with management will be held the same day at 8:30 a.m. (Eastern Time). The call will be broadcast live and available for replay at www.mksinstruments.com. Dial-in numbers are 1-800-218-0204 for domestic callers and 303-262-2130 for international callers. A telephone replay can be accessed for one week at 303-590-3000, pass code 11081576#.

MKS Instruments, Inc. is a leading worldwide provider of process control solutions for advanced manufacturing processes such as semiconductor device manufacturing; thin-film manufacturing for flat panel displays, data storage media, architectural glass and electro-optical products; and technology for medical imaging equipment. Our instruments, components and subsystems incorporate sophisticated technologies to power, measure, control, and monitor increasingly complex gas-related semiconductor manufacturing processes, thereby enhancing our customers' uptime, yield and throughput, and improving their productivity and return on invested capital.

SOURCE MKS Instruments, Inc.

CONTACT: Ron Weigner, Vice President and Chief Financial Officer of MKS
Instruments, Inc., 1-978-284-4446
Web site: http://www.mksinstruments.com
(MKSI)