ATMI Reports First Quarter Results; Earnings Per Share Increase 85%.

DANBURY, Conn.--(BUSINESS WIRE)--April 22, 1998--ATMI, Inc. (NASDAQ:ATMI), today announced revenues of $27,400,000 for 1998's first quarter, a 22% increase from revenues of $22,500,000 in the comparable period last year. Net income increased 77% to $4,465,000, compared with last year's $2,516,000. Earnings per share were $.24 on a diluted basis, or 85% higher than last year's $.13 per share. ATMI's financials do not include the previously announced proposed acquisition of NOW Technologies, Inc.

Gene Banucci, CEO said, "ATMI's product mix shifted as expected during the first quarter. Overall equipment and contract revenues declined, while our higher margin consumable revenues--led by the SDS?Gas Source delivery system products--continued to grow. We see equipment revenues continuing to slow over the next few quarters. However, semiconductor unit demand--which drives our consumables business--has, thus far, remained strong. Recently, we have seen a significant slowing at wireless device manufacturers, but logic, memory, and specialty device manufacturers continue to require record levels of ATMI materials."

Dan Sharkey, CFO commented, "Even though industry requirements for new capacity have softened considerably since the fourth quarter of 1997, ATMI's first quarter results were driven by continued strong demand for its consumable products. The SDS? Gas Source product line helped lead ATMI's earnings growth with nearly a 15% sequential revenue increase. ATMI netted almost $63 million from our previously announced follow-on stock offering of 2.26 million shares, which we completed and closed at the end of the quarter. We hope to close our acquisition of NOW Technologies, Inc. during the second quarter following the satisfaction of customary conditions, when we will have a one-time charge of approximately $2 million for fees and other costs associated with the transaction."

ATMI provides products and services for semiconductor device manufacture, including thin film materials and delivery systems marketed through ADCS, environmental equipment marketed through EcoSys, thin film deposition services marketed through Epitronics, and sub-atmospheric gas delivery systems marketed through NovaSource.

Statements which are not historical information are forward looking, and involve risks and uncertainties, including, but not limited to: changes in semiconductor industry growth or ATMI's markets; competition, problems, or delays developing and commercializing new products, and other factors discussed in ATMI's filings with the Securities and Exchange Commission.

-0-

http://www.atmi.com

-0-

                              ATMI, INC.
                     SUMMARY FINANCIAL INFORMATION

                                            Three Months Ended
                                                 March 31,
                                            1998          1997

Revenues
  Product revenues                   $25,021,000   $19,895,000
  Contract revenues                    2,355,000     2,618,000
Total revenues                        27,376,000    22,513,000
Cost of revenues                      12,346,000    11,487,000
Gross profit                          15,030,000    11,026,000
Operating expenses
  R & D                                2,788,000     2,465,000
  S, G, & A                            5,590,000     5,155,000
                                       8,378,000     7,620,000
Operating income                       6,652,000     3,406,000
Other income                              41,000        30,000
Income before taxes                    6,693,000     3,436,000
Income taxes                           2,228,000       920,000
Net income                           $ 4,465,000   $ 2,516,000
Net income per share
    - diluted                             $ 0.24        $ 0.13
Weighted average
  shares outstanding                  18,853,000    18,732,000

-0-

Balance Sheet Highlights

                             March 31, 1998     December 31, 1997
Assets
Cash & marketable securities   $ 84,060,000     $   29,011,000
 Other current assets            33,828,000         31,571,000
 Other assets                    43,585,000         42,564,000
      Total assets            $ 161,473,000     $  103,146,000

Liabilities and stockholders'
 equity
   Current liabilities        $  17,960,000     $   20,649,000
   Other liabilities             20,702,000         20,625,000
  Stockholders' equity          122,811,000         61,872,000
        Total liabilities &
              stockholders'   $ 161,473,000     $  103,146,000
               equity

CONTACT: Dean Hamilton

ATMI

203/794-1100

[e-mail]