|July 1969||Founded as ELCO Co., Ltd. (Capital 2.5 million yen)
ELCO stood for "Electronics" and "Control" – our main business being the use of electronics to control devices.
|February 1970||Opened Tokyo Sales Office (became a branch in February 1971)|
|July 1973||Built two-story steel-framed Head Office (total floor area 607 m2) in Kami-Akae Machi, Toyama City, Toyama Prefecture (area 3,487 m2)
|August 1977||Opened Osaka Sales Office (became a branch in November 1986)|
|April 1978||Introduced QC Circle activities
Began with 16 circles.
|June 1978||Began to specialize in power supply business.|
|July 1980||Acquired 5,502 m2 of land next door to Head Office, and began operations at three-story, steel-framed 2,723 m2 plant.
|May 1982||Introduced TQC (Total Quality Control)|
|June 1983||Opened Nagoya Sales Office (became a branch in May 1992)
Introduced Policy Management (definition of Long-term Policy and Annual Policy)
|July 1985||Opened Tama Sales Office|
|March 1988||Introduced Toyota Manufacturing Method|
|March 1989||Completed Tateyama Factory in Tateyama Machi, Toyama Prefecture
|May 1990||Established U.S. ELCO., INC. (currently COSEL U.S.A., INC.) in San Jose, California, targeting Silicon Valley, where high-tech industry and venture companies are present in high concentrations.|
|September 1990||Opened Kyoto Sales Office|
|April 1992||Company name changed from ELCO Co., Ltd. to COSEL Co., Ltd.
|June 1993||Accredited under International Standard ISO 9001, relating to quality control and quality assurance (the first accreditation in Toyama Prefecture).|
|December 1994||Shares in the Company registered.
Additional financing brought capital to 2.055 billion yen.
|May 1996||Introduced TMP.|
|May 1997||Extension offices in Saitama and Nagano changed to Sales Offices.|
|July 1997||Established COSEL EUROPE GmbH, a sales subsidiary in Germany.|
|May 1998||Established COSEL ASIA LTD., a sales subsidiary in Hong Kong.|
|January 1999||Shares listed on the Tokyo Stock Exchange and Nagoya Stock Exchange Market Division 2.|
|November 1999||Won TPM Excellence 1st Category.|
|December 1999||Acquired accreditation under International Standard ISO 14001, relating to environmental activities.|
|May 2000||Shares listed on the Tokyo Stock Exchange and Nagoya Stock Exchange Market Division 1.|
|May 2002||Head Office extended to a four-story, steel-framed building (total area 3,842.36 m2).
|November 2002||Established COSEL Shanghai Electronics Co., Ltd., a sales subsidiary in Shanghai, China.|
|May 2004||Branches and Extension offices closed, and all sales locations unified into "Sales Offices."|
|December 2004||Opened Hamamatsu Sales Office.|
|December 2004||Group-wide Quality Control (GWQC) activities begin, to include partner companies.|
|March 2005||Began noise filter business.|
|December 2005||Won the QC Circle Ishikawa Kaoru Award for the first time.|
|February 2006||Completed compliance with RoHS instructions.|
|October 2006||Won the QC Circle Managers Award.|
|May 2007||Tateyama Factory extended to a two-story, steel-framed building (total area 5,259.68 m2).
|February 2008||Won the Gold Award at the JHS All-Japan QC Circle Championships.|
|November 2011||Established SHANGHAI COSEL INTERNATIONAL TRADING CO., LTD., an export subsidiary in Shanghai, China.|
|December 2011||Established WUXI COSEL ELECTRONICS CO., LTD., a manufacturing subsidiary in Jiangsu Province, China.|
|June 2013||Kyoto and Kobe Sales Offices merged with Osaka Sales Office.|
|November 2013||Tachikawa and Atsugi Sales Offices merged with Kawasaki Sales Office.|
|December 2013||Kawasaki Sales Office changed name to Metropolitan Area Sales Office. Hamamatsu Sales Office moved and changed name to Shizuoka Sales Office.|
|August 2015||Completed incorporation of Vietnam Plant. Cosel Vietnam Co., Ltd., a transformer-manufacturing subsidiary.|