Exhibit 10.3

AMENDMENT TO EMPLOYMENT AGREEMENT

This AMENDMENT (the “Amendment”) to the Employment Agreement is made this 29 day
of October, 2018, by and between MKS Instruments, Inc., a Massachusetts
corporation (“MKS”) and John Lee of Lexington, MA (“Employee”).

WHEREAS, MKS and Employee are parties to an employment agreement effective
May 9, 2018 (the “Employment Agreement”); and

WHEREAS, MKS and Employee wish to modify certain provisions of the Employment
Agreement relating to Employee’s eligibility for severance pay and benefits;

NOW THEREFORE, for good and valuable consideration, the sufficiency and receipt
whereof are hereby acknowledged, the parties agree as follows:

1.    In Section 6(d) of the Employment Agreement, the words “a minimum of 6
months of Base Salary or two weeks of Base Salary per year of service, whichever
is greater, in either case” are deleted and replaced with the words “12 months
of Base Salary”.

2.    In Section 6(d) of the Employment Agreement, the following new sentence is
added immediately after the first sentence: “If the Company terminates
Employee’s employment and provided that all of the immediately foregoing
conditions, (i)-(iii), are satisfied, the Company shall also continue to pay for
any medical, dental and/or vision insurance that Employee elects to continue
receiving under COBRA for twelve (12) months after the last full day Employee
works prior to the effective date of Employee’s termination under this
Employment Agreement, less the premium contribution paid by similarly-situated
active employees who are enrolled in comparable coverage.”

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3.    Except as modified in paragraphs 1 and 2 above, the Employment Agreement
shall remain unchanged. To avoid any doubt and without limitation of any kind,
the parties acknowledge and agree that this Amendment is not intended to, and
shall not, have any effect on Employee’s obligations under Section 7 of the
Employment Agreement, notwithstanding the enactment of Section 24L of Chapter
149 of the Massachusetts General Laws or any other change in the law after the
parties entered into the Employment Agreement. To ensure that MKS’s ability to
enforce the post-employment restrictions set forth in Section 7 of the
Employment Agreement is in no way diminished by the parties entering into this
Amendment, Employee agrees that MKS may (if it deems advisable in its sole
discretion) add to the General Release referred to in Section 6(d) of the
Employment Agreement post-employment restrictions identical to the
post-employment restrictions set forth in Section 7 of the Employment Agreement.

In witness whereof, the parties hereto have executed, in the Commonwealth of
Massachusetts, this Amendment as a sealed instrument, as of the date first
written above.

 

MKS INSTRUMENTS, INC. By:   /s/ Gerald G. Colella   Chief Executive Officer  
/s/ T. C. Lee   John Lee

 

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