EXHIBIT 99.1

ATMI Reports Record Revenues and Net Income for Third Quarter 2012

DANBURY, Conn., Oct. 24, 2012 (GLOBE NEWSWIRE) -- ATMI, Inc. (Nasdaq:ATMI) today reported record revenues and net income for the third quarter of 2012.

Revenues were $108.8 million during the third quarter of 2012 compared with $95.0 million last year, due to the positive contribution from last year's SDS^® Direct transaction, strong demand for single-use equipment in LifeSciences, and royalties recognized in the quarter. Net income for the quarter was $14.4 million, or $0.44 per diluted share, compared with $8.0 million, or $0.25 per diluted share, during the prior year period.

"We clearly encountered a bit of a headwind in the Microelectronics markets that impacted wafer starts during the third quarter," said Doug Neugold, Chief Executive Officer. "Against that backdrop, our SDS Direct transaction continued to perform in line with expectations and our customers are moving forward with production plans for the 28nm and 20nm nodes, where we are well positioned with leading-edge products. LifeSciences revenues, while down from the previous quarter as expected given the European seasonal effect, were strong versus the prior year as customers continue to adopt our single-use technology."

Segment Results (all comparisons to same period in 2011)

Microelectronics

• Revenues grew 15 percent to $98.5 million
• Results included $7.4 million incremental revenues from SDS Direct and a $2.6 million royalty
• Operating income grew 41 percent due to revenue growth, the royalty, and completion of a collaborative development agreement

LifeSciences

• Revenues improved 13 percent to $10.4 million
• Strong demand for single-use equipment, which will benefit future periods as consumables ramp when customers begin high-volume manufacturing
• Operating loss due to continued investment in new product development

Market Environment

"Consistent with external data points, we anticipate wafer starts to be down seasonally in the fourth quarter, impacting Microelectronics," commented Neugold. "However, longer term trends remain favorable as customers increase production at advanced nodes. We are investing in a new manufacturing facility in Korea to work more closely with our Asian customers. LifeSciences is on track for a strong finish to the year after the seasonally soft third quarter, with long-term growth driven by the move to high-volume production using single-use technology. Given the macroeconomic uncertainties, we will continue to closely monitor and control our discretionary cost structures in the near term."

Webcast Information

A conference call (dial-in: 877.766.0748) discussing the Company's financial results and business outlook will begin at 11:00 a.m. Eastern time, October 24, 2012. A replay of the call will be available for 48 hours at 855.859.2056 (access code 41878233). An audio webcast of the conference call will be available for 30 days on http://investor.atmi.com.

About ATMI

ATMI, Inc. provides specialty semiconductor materials, and safe, high-purity materials handling and delivery solutions designed to increase process efficiencies for the worldwide semiconductor, flat panel, and life sciences industries. For more information, please visit http://www.atmi.com.

The ATMI, Inc. logo is available at http://www.globenewswire.com/newsroom/prs/?pkgid=5254

ATMI, the ATMI logo, and SDS are trademarks or registered trademarks of Advanced Technology Materials, Inc., in the United States, other countries, or both.

Forward Looking Statements

Statements contained herein that relate to ATMI's future performance, including, without limitation, statements with respect to ATMI's anticipated results of operations or level of business for 2012 or any other future period, are forward-looking statements within the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Such statements are based on current expectations only and are subject to certain risks, uncertainties, and assumptions, including, but not limited to, changes in semiconductor and life sciences industry growth (including, without limitation, wafer starts) or ATMI's markets; competition, problems, or delays developing, commercializing, and delivering new products; customer-driven pricing pressure; potential loss of key customers; problems or delays in integrating acquired operations and businesses; uncertainty in the credit and financial markets; ability to protect ATMI's proprietary technology; and other factors described in ATMI's Form 10-K for the year ended December 31, 2011 and other subsequent filings with the Securities and Exchange Commission. Such risks and uncertainties may cause actual results to differ materially from those expressed in our forward-looking statements. ATMI undertakes no obligation to update any forward-looking statements.

CONTACT: Troy Dewar
         Director, Investor Relations
         203.207.9349
         tdewar@atmi.com