UNITED STATES
                                 SECURITIES AND EXCHANGE COMMISSION
                                              WASHINGTON, D.C. 20549


     DIVISION OF
CORPORATION FINANCE


                                                                March 14, 2019

  By E-Mail

  Mark Gordon, Esq.
  Wachtell, Lipton, Rosen & Katz
  51 West 52nd Street
  New York, NY 10019

          Re:     Entegris, Inc.
                  Registration Statement on Form S-4
                  Filed on February 28, 2019
                  File No. 333-229931

  Dear Mr. Gordon:

         We have limited our review of your registration statement to those
issues we have
  addressed in our comments. In some of our comments, we may ask you to provide
us with
  information so we may better understand your disclosure.

         Please respond to this letter by amending your registration statement
and providing the
  requested information. If you do not believe our comments apply to your facts
and
  circumstances or do not believe an amendment is appropriate, please tell us
why in your
  response.

         After reviewing any amendment to your registration statement and the
information you
  provide in response to these comments, we may have additional comments.

  Summary, page 15

  1.      Please revise the disclosure relating to the governance of the
combined company on page
          22 and elsewhere in your registration statement to state who will
select the four
          individuals designated by each company to serve on the board of
directors of the
          combined company and the basis upon which those individuals will be
selected.

  2.      Please revise the disclosure relating to the regulatory approvals
necessary to close the
          merger on page 24 and elsewhere in your registration statement to
state the foreign
          jurisdictions from which you will need such approval.

  The Merger, page 77

  3.      We note that the disclosure under the caption "Certain Estimated
Synergies" (page 115)
          you disclose estimated synergies from the merger within 12 months of
the closing of $75
 Mark Gordon, Esq.
Wachtell, Lipton, Rosen & Katz
March 14, 2019
Page 2

       million. We note in your letter to shareholders dated March 8, 2019 that
your estimate of
       synergies is currently $125 million. Please update your disclosure in
the registration
       statement.

Form of Proxy Card

4.     Please revise the forms of proxy to clearly identify each as being
preliminary. Refer to
       Rule 14a-6(e)(1) of Regulation 14A.

        We remind you that the filing persons are responsible for the accuracy
and adequacy of
their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration
statement.

       Please direct any questions to me at (202) 551-3619.

                                                            Sincerely,

                                                            /s/ Daniel F.
Duchovny
                                                            Daniel F. Duchovny
                                                            Special Counsel
                                                            Office of Mergers
and Acquisitions