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Our Business

We aim to contribute to society by making effective use of our unique resources to maintain the comfort and convenience of people's daily lives. To that end, we manufacture and sell:

Diatomite and Perlite Filter aids, our core technology, used to remove particulate from liquids and gases;
High purity, specialty diatomite filter aids for liquid filtration applications where specifications call for an extra low solubility level.
Functional Additives for use in coatings, agricultural chemicals,and other industrial products.

Plants and Mines

 We mine and process diatomite filter aids and fillers at three conveniently located sites in Japan: Akita, Okayama and Oita Prefectures.

 In addition we are operating a diatomite plant in Jilin Province, Northeast China, which is dedicated to the Chinese domestic market and Exports to Asia and other parts of the world.

 We also operate near Osaka a Specialty plant dedicated to the production of High Purity Filter Aids for the pharmaceutical and beverage markets.

 We own two perlite mines in Akita and Yamagata Prefectures and process perlite ore at our Tochigi Plant.


  • 1930
    Okayama Plant Built

  • 1933
    Radiolite® Trademark established in Japan

  • 1943
    Kurayoshi Plant built

  • 1953
    Establish a Research and Development center

  • 1960
    Akita Plant built

  • 1965
    Initiated Perlite business

  • 1966
    Oita Plant built

  • 1967
    New plant built in Okayama

  • 1971
    Showa Listed on Second Section, Tokyo Stock Exchange

    Showa Listed on Second Section, Nagoya Stock Exchange

  • 2010
    Establishment of Joint Venture and Radiolite Trading Co., Ltd. in China