1
                                                                    EXHIBIT 99.1

                        ATMEL AND SIEMENS SIGN ONE AND A
                 HALF BILLION DOLLAR, FOUR YEAR SUPPLY AGREEMENT


PRESS RELEASE

LONDON--(BUSINESS WIRE)--Sept. 18, 2000--Atmel Corporation (Nasdaq:ATML -
news) and Siemens AG last month concluded a framework purchasing agreement which
could see Atmel become a significant semiconductor supplier to Siemens in
support of their expanding product offerings. Under the agreement, Atmel agrees
to sell and Siemens agrees to buy $1.5 billion of products over the next four
years.

Atmel has also agreed to acquire specific manufacturing assets, including a
fabrication plant and some equipment in North Tyneside, England. This will
facilitate the appropriate manufacturing infrastructure and production output to
support the Siemens requirement.

George Perlegos, Atmel's President and Chief Executive Officer said, "The
signing of this supply agreement strengthens the relationship between the two
companies. Atmel is delighted to be associated with Siemens in this venture,
which also will help us grow our design and manufacturing presence in Europe."

Atmel will install CMOS, BiCMOS and Silicon Germanium process technology in the
new fab and will manufacture .18 micron 8 inch wafers for non-volatile memory
and microcontroller products.

Specific financial terms of the agreements were not disclosed.

About Atmel

Founded in 1984, Atmel Corporation is headquartered in San Jose, California with
manufacturing facilities in Colorado Springs, Colorado, Nantes and Rousset,
France and Heilbronn, Germany. Atmel designs, manufactures and markets on a
worldwide basis advanced logic, mixed-signal, non-volatile memory, and RF
semiconductors. Atmel is also a leading provider of system level integration
semiconductor solutions using advanced CMOS, BiCMOS, BiPolar and SiGe process
technologies.

Atmel product and financial information are available from its Fax-on-Demand
service. In North America call 1-800-292-8635 or Internationally, call
1-408-441-0732. Requests may be made via e-mail to literature@atmel.com or by
visiting Atmel's web site at www.atmel.com.

Note to Editors: Atmel, the Atmel logo and combinations thereof and others
contained herein, are trademarks of Atmel Corporation.

Terms and product names in this document may be the trademarks of others.

Contact:

     Atmel
     Bob Henderson, 408/451-2855
     bhenderson@atmel.com