When an access process has been requested for a storage apparatus, a registration unit determines an access priority of the requested access process and registers an entry corresponding to the requested access process in a queue corresponding to the determined access priority out of a plurality of queues that are each provided for a different access priority. An instruction unit checks the plurality of queues at intermittent check timing, fetches, at each check timing, one entry from each queue, out of the plurality of queues, in which entries are registered, and instructs the storage apparatus to execute access processes corresponding to the fetched entries.