To provide a storage system capable of minimizing a performance deterioration, saving power consumption, and realizing a high reliability. A storage system according to the present invention includes a computer, a storage apparatus 1 connected with the computer, and a storage management apparatus connected to the storage apparatus, the storage apparatus including a hard disk unit to control a data write operation and a data read operation between the computer and the hard disk unit, and control on/off states of power supply of the hard disk unit on a group basis, and the system management apparatus collecting running information about the computer and computer execution job information for each computer, and determining an on/off time of the power supply of the hard disk unit on the group basis to record the collected information and the on/off time of the power supply on the group basis.