A processor executes a procedure including performing a repair process including first detecting whether there is any abnormality in data read out from a first storage, repairing abnormal data that is the data in which abnormality is detected as a result of the first detection, and storing the repaired data in a second storage area, second detecting when an address of data changed in the repair process and an address of a read-out source of the abnormal data in the first storage area match, whether there is any abnormality in data read out from an area indicated by the address of data changed in the repair process and the address of the read-out source of the abnormal data in the first storage area, repairing and storing, in the second storage area, the data in which abnormality is found as a result of the second detection.