--------------------------------------------------------------------------------
Exhibit 23.3
--------------------------------------------------------------------------------
Consent of Independent Accountants
We hereby consent to the incorporation by reference in this Registration
Statement on Form S-8 of ATMI, Inc. of our report dated May 17, 1997, except for
the last paragraph of Note 3 which is as of July 29, 1997 and the last paragraph
of Note 6 which is as of December 18, 1997, pertaining to the combined financial
statement of Xxxxxxxx Semiconductor Laboratories, Inc. and Affiliate included in
ATMI, Inc.'s Annual Report on Form 10-K for the year ended December 31, 1997. It
should be noted, however, that such financial statements are not included
separately in the form 10-K. We also consent to the application of such report
to the Financial Statement Schedule for the two years ended December 31, 1996
included in the Form 10-K when such schedule is read in conjunction with the
financial statements referred to in our report. The audits referred to in such
report also included this schedule.
/s/ Price Waterhouse LLP
Phoenix, Arizona
March 31, 1998
