| 1883 | Saito Manufacturing is Established by founding President Hajime Saito, and begins producing medical equipment. --- |
| 1933 | The company is reorganized as Saito Saito Manufacturing Co., Ltd. --- |
| 1934 | The company name is changed to Showa Manufacturing Co., Ltd. --- |
| 1982 | Plant reorganization commences. The second construction phase of the Umi Plant and construction of the Koga Plant and head office begin. --- |
| 1983 | The head office and the Umi and Koga Plants are completed. --- |
| 1984 | The " 101 Shinsei Undo " target system and Toyota production methods are implemented. --- |
| 1987 | Company operations are reorganized into separate divisions. --- |
| 1990 | Company stocks are listed on the Fukuoka Stock Exchange on December 25. --- |
| 1991 | Began manufacture of glass-lined water boilers. Received 1st Urban Landscape Award Grand Prix for the Fukuhaku Deai Bridge in the middle of the Tenjin - Nakasu promenade. ----- |
| 1992 | Began manufacture of central control panels for air conditioning system, compact air handling system and trailers. Received 2nd Urban Landscape Award Grand Prix for the railings on the Maizuru-bashi in Karatsu, Saga. --- |
| 1993 | Moved production lines from the Tokyo Plant to the Sapporo Plant. Environmental equipment division started. Began manufacture of the Oyusys commercial bath system. Keiji Mizuguchi appointed as sixth president. --- |
| 1994 | Signed technical agreement with Samsung of Korea. --- |
| 1995 | Established venture company Dalian Bingshan Air Conditioning Equipment Co., Ltd. in Dalian, China. Merged with Showa F Cast. Started manufacturing stainless steel boilers, Slim Pal and Ray-Clear Unit. --- |
| 1996 | Completed Tokyo Branch building. Won Fukuoka Prefectures "Efficient Household Water Supply Utilization System Award". --- |
| 1997 | Started a venture company Dalian Bingshan Air Conditioning Equipment Co., Ltd. in China. Urbanex Type FT functional guard fence is awarded Gold Prize (Good Design Product), Urbanex SP Series street furniture system is selected as Good Design Product and Local Station LST-24 is selected as Good Design Product by Ministry of International Trade and Industry Japan. --- |
| 1998 | Established Showa Maintenance Service. Launched Thermodevices Division. Started manufacturing household water recycle system Eco Life, infrared ultra thin heater panel and IR Cera-Flex heater. Urbanex GF Series stone cube furniture is awarded Good Design . --- |
| 1999 | Established Hokkaido Showa Manufacturing and Showa Total Service. Made Shinasahi Sangyo a subsidiary. Relocated Sendai office. --- |
| 2000 | Established Asahi Tech as a subsidiary. Thermodevices Division moved to Hisayama Plant. --- |
| 2001 | Shunichi Yamamoto appointed as the seventh president. Established Clean Support. |
| 2002 | Showa Maintenance Service changed its name to Showa Neos. Showa Total Service merged with Asahi Real Estate. |