ATMI Augments Existing Semiconductor Facility to Manufacture Ultraclean, Single-Use...

ATMI Augments Existing Semiconductor Facility to Manufacture Ultraclean,
Single-Use Bioprocess Products for Life Science Customers in the United States

LA JOLLA, Calif., June 1, 2009 (GLOBE NEWSWIRE) -- ATMI, Inc. (Nasdaq:ATMI)
today announced plans to double its global production capacity of ultraclean,
disposable bioprocess vessels for life sciences applications through upgrades
and modifications to its North American manufacturing facility in Bloomington,
Minn. The site, which supplies products for the integrated circuit (IC) and flat
panel display (FPD) markets, adds a Grade B clean room for fabricating complex
three-dimensional storage, mixing and bioreactor vessels for life sciences
customers. In addition to maintaining its current IC and FPD operations, the
plant upgrade will entail creation of an on-site quality testing laboratory.

"ATMI has been developing and manufacturing one-time use mixing, reactor and
storage solutions for the life sciences market for the past few years," said
Doug Neugold, ATMI Chief Executive Officer. "As a result of successfully placing
multiple qualification units with key North American customers -- and their
increasing application of this technology in development and manufacturing --
we're accelerating our investments for production here."

The company will continue its present manufacturing of bioprocess vessels at the
ATMI LifeSciences plant in Belgium. By using copy-exact methods from that
facility, the company can swiftly replicate a CGMP (Current Good Manufacturing
Practices) operation in Minnesota and bring it online -- effectively doubling
its global bioprocess vessel capacity. The time-frame targeted for qualifying
North American production is 4Q 2009; commercial products are expected to ship
in 2010.

"Our customers have asked us to provide them with greater disposable bioprocess
vessel capacity, along with global contingency and continuity of supply for
their critical ultraclean bioprocess storage, mixing and bioreactor vessels,"
said Mario Philips, General Manager of ATMI LifeSciences. "Increasing our
manufacturing footprint addresses the rapidly increasing demands of the
biopharmaceutical marketplace."

Beyond its new Grade B clean room, the upgraded North American facility will
house a bio-burden test laboratory to analyze and manage sterility levels in the
manufacturing environment. With these additions, ATMI continues to capitalize on
its proficiency in semiconductor, clean room and ultrapure manufacturing and to
leverage that expertise in the life sciences market.

About ATMI LifeSciences

ATMI LifeSciences is a leader in single-use mixing, storage, and bioreactor
technology, fluoropolymer-based products, and custom-engineered, flexible
packaging solutions. The business's fundamental knowledge of polymers, specially
selected resins, and its clean room manufacturing experience coalesce to help
drive optimum performance in critical disposable process operations. For more
information, please visit www.atmi-lifesciences.com.

About ATMI

ATMI, Inc. provides specialty semiconductor materials, and 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.

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

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

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 2009 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 industry
growth (including, without limitation, wafer starts) or ATMI's markets;
competition, problems, or delays developing, commercializing and delivering new
products; problems or delays in integrating acquired operations and businesses;
uncertainty in the credit and financial markets; and other factors described in
ATMI's Form 10-K for the year ended December 31, 2008, 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.

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CONTACT: ATMI, Inc.
Dean Hamilton, Director, ATMI Investor Relations
& Corporate Communications
203.207.9349
203.794.1100 x4202
dhamilton@atmi.com