A degeneration control device that controls degeneration of a cache having a plurality of ways based on an error that occurs in response to an access request, includes a cache line degeneration information memory unit, which stores cache line degeneration information that indicates whether a cache line constituting each of the plurality of ways is degenerated, and a degeneration control unit, which writes, when an error that occurs in response to the access request causes a predetermined condition to be met, cache line degeneration information that indicates a predetermined cache line where the error occurs is degenerated in the cache line degeneration information memory unit.