ATMI, INC.                          SUMMARY FINANCIAL INFORMATION
  |---------------------+------------+-----------+-------------+-----------| |                     |            |   Three   |             |Six Months | |                     |            |  Months   |             |   Ended   | |                     |            |   Ended   |             | June 30,  | |                     |            | June 30,  |             |           | |---------------------+------------+-----------+-------------+-----------| |                     |    2001    |    2000   |     2001    |    2000   | |---------------------+------------+-----------+-------------+-----------| |                     |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Revenues            |$ 55,027,000|          $|$ 132,308,000|          $| |                     |            | 71,142,000|             |134,169,000| |---------------------+------------+-----------+-------------+-----------| | Cost of revenues    |  31,137,000| 33,188,000|   68,932,000| 62,917,000| |---------------------+------------+-----------+-------------+-----------| | Gross profit        |  23,890,000| 37,954,000|   63,376,000| 71,252,000| |---------------------+------------+-----------+-------------+-----------| | Operating expenses  |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| |   R & D             |   8,077,000|  7,006,000|   15,998,000| 12,990,000| |---------------------+------------+-----------+-------------+-----------| |   S, G, & A         |  17,185,000| 17,273,000|   37,864,000| 32,158,000| |---------------------+------------+-----------+-------------+-----------| |                     |  25,262,000| 24,279,000|   53,862,000| 45,148,000| |---------------------+------------+-----------+-------------+-----------| | Operating income    | (1,372,000)| 13,675,000|    9,514,000| 26,104,000| |---------------------+------------+-----------+-------------+-----------| | Other income        |   1,092,000|  1,842,000|    2,581,000|  2,730,000| |---------------------+------------+-----------+-------------+-----------| | Income before taxes |   (280,000)| 15,517,000|   12,095,000| 28,834,000| |---------------------+------------+-----------+-------------+-----------| | Income taxes        |   (146,000)|  5,748,000|    4,310,000| 10,638,000| |---------------------+------------+-----------+-------------+-----------| | Net income from     |   (134,000)|  9,769,000|    7,785,000| 18,196,000| | operations          |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| |                     |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Net one-time items, |            |           |             |           | | including           |           -|          -|  (4,878,000)|          -| | restructuring, net  |            |           |             |           | | of tax              |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Net investment      |            |           |             |           | | gains, net of tax   |     995,000|          -|      995,000|  5,210,000| |---------------------+------------+-----------+-------------+-----------| |                     |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Net income          |   $ 861,000|          $|  $ 3,902,000|          $| |                     |            |  9,769,000|             | 23,406,000| |---------------------+------------+-----------+-------------+-----------| |                     |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Diluted earnings per|            |           |             |           | | share before        |        $.00|       $.32|         $.26|       $.61| | one-time items      |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| |                     |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Diluted earnings per|            |           |             |           | | share               |        $.03|       $.32|         $.13|       $.78| |---------------------+------------+-----------+-------------+-----------| |                     |            |           |             |           | |---------------------+------------+-----------+-------------+-----------| | Weighted average    |            |           |             |           | | shares outstanding  |  30,762,000| 30,849,000|   30,634,000| 30,081,000| |---------------------+------------+-----------+-------------+-----------|
  |-------------------------------------+--------------+---------------| |       Balance Sheet Highlights      |   June 30,   |  December 31, | |                                     |     2001     |      2000     | |-------------------------------------+--------------+---------------| |       Assets                        |              |               | |-------------------------------------+--------------+---------------| |         Cash & marketable securities|$  115,333,000| $  131,505,000| |-------------------------------------+--------------+---------------| |         Accounts receivable         |53,429,000    |     70,282,000| |-------------------------------------+--------------+---------------| |         Inventory                   |41,889,000    |     39,404,000| |-------------------------------------+--------------+---------------| |         Other current assets        |15,484,000    |     16,232,000| |-------------------------------------+--------------+---------------| |            Total current assets     |226,135,000   |    257,423,000| |-------------------------------------+--------------+---------------| |         Fixed assets, net           |120,280,000   |     80,332,000| |-------------------------------------+--------------+---------------| |         Other assets                |14,585,000    |     13,050,000| |-------------------------------------+--------------+---------------| |              Total assets           |$ 361,000,000 |  $ 350,805,000| |-------------------------------------+--------------+---------------| |                                     |              |               | |-------------------------------------+--------------+---------------| |      Liabilities and stockholders'  |              |               | |      equity                         |              |               | |-------------------------------------+--------------+---------------| |         Accounts payable            |$  19,680,000 |  $  23,161,000| |-------------------------------------+--------------+---------------| |         Short-term debt             |6,933,000     |      7,834,000| |-------------------------------------+--------------+---------------| |         Other current liabilities   |23,934,000    |     23,468,000| |-------------------------------------+--------------+---------------| |           Total current liabilities |50,547,000    |     54,463,000| |-------------------------------------+--------------+---------------| |         Other long-term liabilities |18,149,000    |      9,775,000| |-------------------------------------+--------------+---------------| |         Stockholders' equity        |292,304,000   |    286,567,000| |-------------------------------------+--------------+---------------| |            Total liabilities &      |$ 361,000,000 |  $ 350,805,000| |      stockholders' equity           |              |               | |-------------------------------------+--------------+---------------| |