| November 1953 |
Ryosan Denki Co., Ltd. (a limited liability company) is established in Kanda-Suehirocho, Chiyoda-ku, Tokyo. |
| March 1957 |
Following reorganization to a stock company, Ryosan Denki Co., Ltd. is established. |
| January 1959 |
The Company's head office is moved to Kanda-Matsuzumicho, Chiyoda-ku, Tokyo. |
| October 1963 |
Ryosan Trading Co., Ltd. is established. |
| December 1963 |
The head office is moved to a new building in Soto-Kanda, Chiyoda-ku, Tokyo (now Soto-Kanda Building). |
| February 1974 |
Hong Kong Ryosan Limited is established. |
| June 1976 |
Singapore Ryosan Private Limited is established. |
| January 1979 |
Ryotai Corporation is established in Taiwan. |
| October 1981 |
The company name is changed to Ryosan Co., Ltd. |
| July 1983 |
Stock is listed on the Second Section of the Tokyo Stock Exchange. |
| March 1986 |
Stock is listed on the First Section of the Tokyo Stock Exchange. |
| April 1988 |
Ryosan Trading Co., Ltd. is absorbed by merger. |
| April 1996 |
Ryosan Technologies USA Inc. is established. |
| November 1997 |
Zhong Ling International Trading (Shanghai) Co., Ltd. is established. |
| November 1999 |
Kawasaki Comprehensive Business Center is established.
|
| March 2000 |
The head office is moved to the Head Office Building at Higashi-Kanda, Chiyoda-ku, Tokyo.
|
| February 2001 |
Korea Ryosan Corporation is established. |
| November 2001 |
Ryosan (Thailand) Co., Ltd. is established. |
| July 2002 |
Ryosan IPC (Malaysia) Sdn. Bhd. is established. |
| December 2002 |
Dalian F.T.Z Ryosan International Trading Co., Ltd. is established. |
| August 2003 |
All offices obtain ISO 14001 certification. |
| March 2012 |
Ryosan Europe GmbH is established. |
| September 2014 |
Heat sink production business is transferred. |
| September 2014 |
Ryosan India Private Limited is established. |
| June 2016 |
Engineering Headquarters obtain ISO9001 certification. |
| March 2017 |
Edal Electronics Company Limited becomes a wholly owned subsidiary |
| September 2017 |
AIO Core Co., Ltd. is invested. |
| November 2017 |
Qingdao Sanyuan Taike Electronics Co., Ltd. is invested. |
| April 2022 |
Transition to Prime Market in Tokyo Stock Exchange. |
