Lack of knowledge about electricity, medical gases and other hospital installations may cause misuses, errors and mistakes and results in many accidents. There also is neglected risk management system including quality control of medical equipments. Early detection of any abnormality or malfunction of medical equipments mainly due to earlier aging ensures safe clinical operation; therefore it is important to educate medical staffs on electrical devices, hospital installations and trouble shootings. Maintenance and safety control system of medical equipments should be substantially established in every medical institute. This article describes how to construct safety management system for medical equipments and installations, and shows some examples of its trouble.