In order to efficiently utilize processor resources, a storage system according to this invention includes: a protocol processor; a processor; a local router; a first memory; and a disk drive. In the storage system, the protocol processor transmits, upon transmitting a frame to the host computer, information on a transmission state of the frame to the local router, and the local router determines, upon the protocol processor receiving a frame, which of the processors processes the received frame, based on which a subject the received frame requests for an access to, transfers the received frame to the determined processor, determines, upon the protocol processor transmitting a frame, which of the processors processes information on a transmission state of the frame, based on an exchange of the transmitted frame, and transfers the information on the transmission state of the frame to the determined processor.