Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Quirk Brian Charles
 2. Date of Event Requiring Statement (Month/Day/Year)
03/01/2014		 3. Issuer Name and Ticker or Trading Symbol
MKS INSTRUMENTS INC [MKSI]
(Last)
(First)
(Middle)
2 TECH DRIVE, SUITE 201		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Sr. VP, Global Operations
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

ANDOVER, MA 01810		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock 3,152.635
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Restricted Stock Unit   (1)   (1) Common Stock 17,040.25 $ (2) D  
Restricted Stock Unit   (3)   (3) Common Stock 14,428.831 $ (2) D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Quirk Brian Charles
2 TECH DRIVE, SUITE 201
ANDOVER, MA 01810		       Sr. VP, Global Operations  

Signatures

/s/Renee M. Donlan POA 03/06/2014
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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).
(1) The RSUs vest in equal annual installments over three years from the respective original grant date. The amount above comprises of: 2,113.136 which was granted on April 11, 2011; 4,938.407 which was granted on April 2, 2012; 3,962.536 which was granted on February 25, 2013; and 6,026.171 on February 10, 2014.
(2) Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.
(3) 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 of over three years from the respective original grant date. The amount above comprises of 5,389.575 which was granted on on February 25, 2013 and 9,039.256 on February 10, 2014.

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