With the recent deregulation of the electric power market, maintenance services of power generating equipment have also been undergoing significant change. This article introduces various customer services of Mitsubishi Heavy Industries, Ltd. (MHI) that accommodate this change, from the following two perspectives. Feature of change in service: The service of power systems is shifting from the preventive maintenance to the minimum maintenance that is economical and reliable. Notable technical factors such as high reliability, actual operating experience, novelty, etc.: In order to satisfy customer service needs, MHI has developed a range of new services including Plant Asset Management (PAM) as a new maintenance technology, the Mitsubishi Metallurgical Life Assessment System (Auto-MLAS) as a new inspection technology in pace with the times, and Remote Monitoring Support using IT technology.