A storage apparatus writes data to a storage drive or reads data from a storage drive in response to an I/O request sent from a server. The storage apparatus includes a plurality of AC-DC power supplies supplying the storage drive with drive power is provided with a plurality of power supply paths provided for the respective AC-DC power supplies. A plurality of gate units are provided to the respective power supply paths and configured to stop supplying drive power to the storage drive through the corresponding power supply path when detecting voltage abnormality in the drive power supplied from the AC-DC power supply to the storage drive. The power supply paths allow each of the storage drives belonging to a same RAID group to receive the supply of the drive power from the AC-DC power supplies through different power supply paths, respectively.