POWER OF ATTORNEY
Know all by these presents that the undersigned hereby constitutes and appoints
Joseph Colella the undersigned's true and lawful attorney-in-fact to:
 (1)	prepare, execute in the undersigned's name and on the undersigned's
behalf, and submit to the U.S. Securities and Exchange Commission (the SEC)
a Form ID, including amendments thereto, and any other documents necessary or
appropriate to obtain codes and passwords enabling the
undersigned to make electronic filings with the SEC of reports required by
Section 16(a) of the Securities Exchange Act of 1934 or any rule or regulation
of the SEC;
 (2)	execute for and on behalf of the undersigned, in the undersigned's
capacity as an Officer of ENTEGRIS, INC. (the Company), Forms 3, 4, and 5
in accordance with Section 16(a) of the Securities Exchange Act of 1934 and
the rules thereunder, and any other forms or reports the undersigned may be
required to file in connection with the undersigned's ownership, acquisition,
or disposition of securities of the Company;
 (3)	do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such Forms
3, 4, or 5, or other form or report, and timely file such form or report with
the United States Securities and Exchange Commission and any stock exchange or
similar authority; and
 (4)	take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of
the undersigned pursuant to this Power of Attorney shall be in such form and
shall contain such terms and conditions as such attorney-in-fact may approve
in such attorney-in-fact's discretion.
      The undersigned hereby grants to such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might
or could do if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact,
or such attorney-in-fact's substitute or substitutes, shall lawfully do or
cause to be done by virtue of this power of attorney and the rights and powers
herein granted. The undersigned acknowledges that the foregoing
attorney-in-fact, is serving in such capacity at the request of the
undersigned, and is not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.
      This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorney-in-fact.
      IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 4th day of March 2024.

      			/s/ David Reeder
      			David Reeder