Conventionally, no consideration was given to the control of the main power supply circuit in a storage apparatus. Thus, unnecessary electric power will be consumed because it is not possible to inhibit the power consumption of the main power supply circuit of the storage apparatus. With this storage system having a plurality of storage apparatuses, a storage apparatus internally has a power supply control program for controlling the respective components and the main power supply circuit, and the power supply control command program provided to the management computer migrates a storage extent to be used for business to another storage apparatus based on the operation schedule of business to use the storage extent of the storage apparatus, and commands the power supply control of the main power supply circuit in the storage apparatuses and the respective components.