| 1905-08 |
Founded as Tokyo Tsukishima Kikai Seisakusho. |
| 1917-05 |
Changed to a stock company and named Tsukishima Kikai Co., Ltd. |
| 1937-12 |
The company merged with Dai-ni Tsukishima Kikai Co., Ltd. (former Tsurumi Factory), which was located in Tsurumi ward, Yokohama City. |
| 1949-05 |
The company's shares were listed on the Tokyo Stock Exchange (listed in the First Section in October, 1961). |
| 1949-10 |
The Osaka satellite office was opened (current Osaka Sales Branch Office). |
| 1961-10 |
The company's shares were listed on the Second Section of the Osaka Securities Exchange (listed in the First Section in November, 1966). |
| 1961-10 |
Laboratory was opened in Chuo ward, Tokyo. |
| 1971-04 |
The pollution control-related equipment operation and management division was spun off and a subsidiary, Tsukishima Maintenance Co., Ltd., was founded. |
| 1974-03 |
Company was accredited by Minister of Construction (special-48), No. 3484, due to changes in the Construction Industry Act. |
| 1976-01 |
The Ichikawa Factory was opened. |
| 1979-04 |
The construction work division was spun off and a subsidiary, Tsukishima Plant Construction Co., Ltd., was founded. |
| 1979-04 |
The design, manufacturing, and sales divisions of sorting machine, attritor, and metal work machinery and instruments were spun off and Tsukishima Machine Sales Co., Ltd. was founded. |
| 1985-12 |
The Tsurumi Factory was closed due to consolidation of production systems. |
| 1990-11 |
The laboratory was relocated and newly opened in Ichikawa City, Chiba. |
| 1991-02 |
Tsukishima Engineering Malaysia Sdn. Bhd. was founded in Malaysia as a local business office. |
| 1993-04 |
TSK Engineering (Thailand) Co., Ltd.(currently a consolidated subsidiary) was founded in Thailand as a local business office. |
| 1994-11 |
TSK Engineering Taiwan Co., Ltd. was founded in Taiwan as a local business office. |
| 1998-12 |
The company acquired 20% of total issued shares of Kanuma Kankyo-bika Center (current SUN ECO THERMAL Co., Ltd. as a consolidated subsidiary), providing the company's entrance into the waste-disposal industry. |
| 2000-10 |
The Environment Process Development Center was opened in Ichikawa City, Chiba. |
| 2000-11 |
Tsukishima Maintenance Co., Ltd. and Tsukishima Plant Construction Co., Ltd. merged to form Tsukishima Techno Maintenance Service Co., Ltd. (currently a consolidated subsidiary). |
| 2005-03 |
The company acquired 74.6% of total issued shares of Nittetu Chemical Engineering Ltd. (current Tsukishima Kankyo Engineering Ltd.), making it a consolidated subsidiary. |
| 2005-08 |
Tsukishima Techno Machinery Co., Ltd. and former Tsukishima Machine Sales Co., Ltd. were merged to enhance and reinforce the company's equipment service business; Tsukishima Techno Machinery Co., Ltd. was the surviving company. |
| 2006-04 |
Samukawa Water Service Co., Ltd. (currently a consolidated subsidiary), founded through investments made by the company, Tsukishima Techno Maintenance Service Co., Ltd., and others, was fully established. Operations began in the Samukawa Water Purification Plant Drainage special business of the Public Enterprises Agency of Kanagawa Prefecture pursuant to the Act on Promotion of Private Finance Initiative (PFI Act). |
| 2008-12 |
The company merged with Tsukishima Fudosan Co., Ltd., a non-consolidated company. |
| 2011-03 |
TSK Engineering China Co., Ltd. was founded in China as a local business office. (currently a consolidated subsidiary) |
| 2012-07 |
Tsukishima Techno Solution Co., Ltd. acquired the industrial machinery business from Tsukishima Techno Machinery Co., Ltd. and changed its name to Tsukishima Machine Sales Co., Ltd. (currently a consolidated subsidiary). |
| 2012-07 |
Tsukishima Kikai Co., Ltd. merged with Tsukishima Techno Machinery Co., Ltd. in an absorption type merger. |
| 2013-12 |
Headquarters were relocated to the current location. The Environment Process Development Center was closed and that function was integrated with Ichikawa Research & Development Center. |
| 2014-10 |
The company acquired the entire issued share capital of DAIDO CHEMICAL ENGINEERING CORP., making it a subsidiary. |
| 2014-12 |
The company acquired 83.33% share capital of BOKELA GmbH (incorporated in Germany), making it a subsidiary. |
| 2017-04 |
Following the completion of the Inuyama Water Purification Plant, other two water purification plants, and power generation facilities for the Aichi Public Enterprise Bureau pursuant to the Act on Promotion of Private Finance Initiative (PFI Act), operations began at Owari Water & Energy Co., Ltd. (currently a consolidated subsidiary). |
| 2017-07 |
The company acquired the issued share capital of SANSHIN KOGYO Co., Ltd., making it a subsidiary. |
| 2019-04 |
The Muroran Factory was opened. |
| 2021-04 |
Following completion of the sewage sludge fuel conversion facility at the Toba Sewage Treatment Plant ordered by the city of Kyoto as a DBO project, operations began at Biocoal Kyoto Toba Co., Ltd. (currently a consolidated subsidiary), which was founded through investments made by the company and Tsukishima Techno Maintenance Service Co., Ltd. |
| 2022-04 |
Following the restructuring of the Tokyo Stock Exchange's market segments, the company transitioned to the Prime Market. |
| 2023-04 |
Tsukishima Kikai Co., Ltd. transitioned to a holding company structure and was renamed Tsukishima Holdings Co., Ltd. The water environment business was succeeded by Tsukishima Aqua Solutions, while the industrial business was succeeded by Tsukishima Kikai. |
| 2023-04 |
Ichihara Biocycle Co., Ltd. (currently a consolidated subsidiary), which was established through joint investment by the company and others, commenced operations following the completion of facility development for the Matsugashima Terminal Treatment Plant Sewage Sludge Solid Fuel Project. This project was commissioned by the City of Ichihara as a DBO (Design-Build-Operate) initiative. |
| 2023-10 |
Tsukishima Aqua Solution Co., Ltd. merges with JFE Engineering Corporation's domestic water engineering business; renamed Tsukishima JFE Aqua Solution Co., Ltd. |
| 2023-10 |
In addition to Tsukisima & J Aqua Machine and Service Co., Ltd. (formerly JFE Aqua Service Equipment Co., Ltd.), seven special purpose companies (SPCs) involved in PFI and DBO projects were newly consolidated. |
| 2024-04 |
Oyama Energy Cycle Co., Ltd. (currently a consolidated subsidiary), established through investment by Tsukishima JFE Aqua Solutions Co., Ltd. and others, commenced operations following the completion of facility development for sludge treatment and resource recovery at the Oyama Water Treatment Center. This project was commissioned by the City of Oyama as a PFI project. |
| 2024-10 |
Tsukishima Kankyo Engineering Ltd.'s acquisition of DAIDO CHEMICAL ENGINEERING CORP. |
| 2025-02 |
Following the completion of Sewage sludge and other resource utilization project at Iwaki City Chubu Purification Center and related facilities ordered by the city of Iwaki as a Promotion of Private Finance Initiative (PFI Act), operations commenced at Green Cycle Power IWAKI Co., Ltd. (currently a consolidated subsidiary), which was established through investments from the Tsukishima JFE Aqua Solution Co., Ltd. and others. |
