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 *
  Werth Dennis L
 2. Date of Event Requiring Statement (Month/Day/Year)
05/02/2016		 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, Business Units
 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)

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
Stock Appreciation Right   (1) 03/31/2017 Common Stock 5,838 $ 20.32 D  
Stock Appreciation Right   (2) 05/17/2018 Common Stock 4,199 $ 27.79 D  
Stock Appreciation Right   (3) 04/12/2019 Common Stock 5,911 $ 27.89 D  
Stock Appreciation Right   (4) 05/20/2020 Common Stock 10,313 $ 22.39 D  
Restricted Stock Unit   (5)   (5) Common Stock 2,952 $ (5) D  
Stock Appreciation Right   (6) 05/19/2021 Common Stock 8,858 $ 29.8 D  
Restricted Stock Unit   (7)   (7) Common Stock 4,911 $ (7) D  
Stock Appreciation Right   (8) 05/19/2022 Common Stock 7,366 $ 31.13 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Werth Dennis L
2 TECH DRIVE
SUITE 201
ANDOVER, MA 01810		       Sr. VP, Business Units  

Signatures

/s/ M. Kathryn Rickards, attorney-in-fact 05/04/2016
**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) On April 29, 2016, pursuant to the Agreement and Plan of Merger between MKS Instruments, Inc. ("MKS"), MKS' wholly-owned subsidiary, PSI Equipment, Inc. ("Merger Sub") and Newport Corporation ("Newport"), dated February 22, 2016 (the "Merger Agreement"), Merger Sub merged with and into Newport (the "Merger"), with Newport surviving the Merger as a wholly-owned subsidiary of MKS. This stock appreciation right, which has a base value of $20.32 and which became fully vested on March 31, 2013, was assumed by MKS in connection with the Merger and was converted from a stock appreciation right with respect to a total of 9,510 shares of Newport common stock having a base value of $12.47 per share.
(2) This stock appreciation right, which has a base value of $27.79 and which became fully vested on March 31, 2014, was assumed by MKS in connection with the Merger and was converted from a stock appreciation right with respect to a total of 6,840 shares of Newport common stock having a base value of $17.06 per share.
(3) This stock appreciation right, which has a base value of $27.89 and which became fully vested on March 31, 2015, was assumed by MKS in connection with the Merger and was converted from a stock appreciation right with respect to a total of 9,630 shares of Newport common stock having a base value of $17.12 per share.
(4) This stock appreciation right, which has a base value of $22.39 and which became fully vested on March 31, 2016, was assumed by MKS in connection with the Merger and was converted from a stock appreciation right with respect to a total of 16,800 shares of Newport common stock having a base value of $13.74 per share.
(5) These restricted stock units representing the right to receive a total of 2,952 shares of MKS' common stock, which vest on March 31, 2017, were assumed by MKS in connection with the Merger and were converted from restricted stock units representing the right to receive a total of 4,810 shares of Newport's common stock.
(6) This stock appreciation right, which has a base value of $29.80 and which vests in equal 1/3 installments on March 31, 2015, 2016 and 2017, was assumed by MKS in connection with the Merger and was converted from a stock appreciation right with respect to a total of 14,430 shares of Newport common stock having a base value of $18.29 per share.
(7) These restricted stock units representing the right to receive a total of 4,911 shares of MKS' common stock, which vest in two equal installments on March 31, 2017 and March 31, 2018, were assumed by MKS in connection with the Merger and were converted from restricted stock units representing the right to receive a total of 8,000 shares of Newport's common stock.
(8) This stock appreciation right, which has a base value of $31.13 and which vests in equal 1/3 installments on March 31, 2016, 2017 and 2018, was assumed by MKS in connection with the Merger and was converted from a stock appreciation right with respect to a total of 12,000 shares of Newport common stock having a base value of $19.11 per share.
 
Remarks:
Exhibit 24 - Power of Attorney

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