Abstract: A storage device includes a plurality of magnetic disk devices each having a write cache, a processor unit that redundantly stores data, a rebuild execution control unit that performs a rebuild process, a write cache control unit that, at the time of the rebuild process, enables a write cache of a storage device that stores rebuilt data, and a rebuild progress management unit that is configured using a nonvolatile memory and manages progress information of the rebuild process. In the case where power discontinuity is caused during the rebuild process and then power is restored, the rebuild execution control unit calculates an address that is before an address of last written rebuilt data by an amount corresponding to the capacity of the write cache based on the progress information of the rebuild process managed by the progress management unit and resumes the rebuild process from that calculated address.