The Railway Technical Research Institute is promoting research and development for maintenance technologies by regarding the maintenance of facilities as one of the most important subjects for the railway industry. When it revised the medium- and long-term basic plan in 1995, it started a new maintenance project on the technological development for the maintenance of rolling stock, track and trolley wire system, and has promoted research and development for about five years while focusing on the development of element technologies, in order to save manpower and extend the life of facilities by using new materials and establish a new maintenance control system. This paper summarizes the research and development themes and results obtained by the project.