MKS INC — Director's Dealing 2014

Feb 3, 2014

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2014-01-30

Reporting Person: Lee John Tseng-Chung (Sr. VP, HPS, Controls & PFMC)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2014-01-30	Restricted Stock Unit	$	J	884.101	Acquired		Common Stock (884.101)	Direct

Footnotes

F1: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2: This transaction reflects the forfeiture of RSUs due to performance criteria.

F3: These RSUs are subject to the achievement of performance criteria determined in the first year of the grant and thereafter vests in equal annual installments over three years.