September 11, 2008
Mitsui Chemicals, Inc.
Tokuyama Corporation

Mitsui Chemicals and Tokuyama Corporation to Begin Joint Developmentof Silane Gas Manufacturing Process
Mitsui Chemicals, Inc. (“MCI”, Head Office: Minato-ku, Tokyo, President: KenjiFujiyoshi) and Tokuyama Corporation (“Tokuyama”, Head Office: Shibuya-ku,Tokyo, President: Shigeaki Nakahara) announced that they have agreed on the joint
development of a manufacturing process for silane gas.
Silane gas is specialty gas used to form silicon film and silicon dioxide film in themanufacturing process of various electronic devices such as thin film solar cells, ofwhich demand is expected to dramatically grow in the future, semiconductors andliquid crystal displays.
For many years, MCI, as a leading supplier of silane gas, has successfully applied its
outstanding chemical engineering know-how, high quality assurance and specialized
analytical technology and resultingly has provided the market with a world-classproduct. Additionally, MCI has considered wide ranging processes for
manufacturing including an independently-developed process called the Alloying
Method. Tokuyama, meanwhile, has a wide variety of silicon material products madefrom metallic silicon, such as high-grade polysilicon, which is used in semiconductor
production. Tokuyama, a supplier of such products, has been making all-out efforts
to create a manufacturing process for silane gas by fully utilizing its specialty, themanufacturing technology for silicon material products.
The two companies have decided to begin the joint development in order to hasten
the development of a new manufacturing process for silane gas by combining theirextensive knowledge and advanced technologies.
On completion of the joint development technology, the companies are planning tolaunch a joint silane gas business, aiming to satisfy the growing need for silane gas
used in solar cells, a market of which is expected to dramatically expand in thefuture, semiconductors and liquid crystal displays.

MCI has launched its new four-year Mid-term Business Plan (the 08MTP),
commencing in fiscal 2008, which is based on a three dimensional strategy focusing
on Economy, Environment and Society and “The Challenge to Create InnovativeValues” through new technologies. MCI’s Performance Materials Business Sector,
which has dealt with silane gas, upholds the mission to establish high-profitability asa growth driver, especially in high-profit sectors such as Automotive and Industrialmaterials, Information Technology materials and Energy materials. MCI will seek
further growth in the energy market, as its strategic-priority business area, byboosting joint development efforts for silane gas to be used as material in solar cells.
Tokuyama, which celebrated the 90th anniversary of its establishment this year, has
set a corporate vision of “Venture Spirit & Innovation” as it moves toward its
centennial. The company has formulated its Three-year Medium-term ManagementPlan, starting in fiscal 2008, with a “Take Off” stage as its first step. Tokuyama sees“Strengthening of strategically growing businesses” as one of its basic strategies, andtargets “Creation of new businesses,” which focuses on the environment, energy,and electronic materials and components markets. Joint development of the silane
gas manufacturing process is a part of this target. Tokuyama will strive to growespecially in the solar cell materials market, which is expected to expand, by having
the thin-film material in addition to the crystalline material in its product lineup.

Contact ;Mitsui Chemicals, Inc.
CSR & Corporate Communications Div.
TEL : +81-3-6253-2100
Tokuyama Corporation
Corporate Communications & Investor Relations Dept.
TEL : +81-3-3499-8023