1980 CHOSHU is founded by Kaname Okamoto as a manufacturer and distributor of residential equipment. (Capital:\70million)
1981 Solar water heaters, bathtub heaters, hot water systems are released.
1984 Engineers are dispatched to NEC Anelva Corporation to learn cutting-edge vacuum technology.
1985 CHOSHU forms a business tie-up with NEC Anelva Engineering on vacuum mechatronics. CHOSHU is designated as an affiliated factory by NEC yamaguchi.
1993 Hiroshima factory launches operations on cleaning service in Mihara, Hiroshima.
1996 Mechatronics equipment factory (Building B) launches operations in Sanyo, Yamaguchi.
1997 Hiroshima factory is certified for ISO9002.
1998 Solar photovoltaic systems are released.
1999 Mechatronics equipment factory is certified for ISO9001.
2000 Building for vacuum equipment factory and administration (Building A) launches operations in Sanyo, Yamaguchi. (It is renamed to Vacuum and Mechatronics equipment factory.)
2007 Head office is relocated to vacuum and mechatronics equipment factory. (It is renamed to Head office/factory)
High-tech and environmental equipment factory (Building C) launches operation.
2009 Solar photovoltaic division is certified for ISO9001.

Production for photovoltaic module of multicrystalline A series is started.
2010 CHOSHU participates PV Japan 2010 at Pacifico Yokohama.

Production for photovoltaic modules of monocrystalline B series is started.

3MW solar modules are delivered to Fukuyama Solar Power Plant of Chugoku Electric Power Co., Inc.
2011 Solar photovoltaic cell production factory (Building D) is completed at Head office/factory.
2012 Production for photovoltaic modules of monocrystalline C series is started with Independently developed 156mm full-square cells.

An integrated production system from silicon ingot pulling to photovoltaic module assembly is established.