Provided is a storage system, including: one or more disk drives storing data; a disk controller for controlling data access to the disk drive; a power supply controller for autonomously turning off a power source of the disk drive according to the data access status to the disk drive, and autonomously turning on the power source of the disk drive, which was turned off, after the lapse of a prescribed period from the time the power source was turned off irrespective of the data access status to the disk drive; and a media inspection unit for inspecting a failure in the disk drive in which the power source thereof was autonomously turned on irrespective of the data access status to the disk drive.