An object is to improve reliability and availability of a storage system.A single service processor (SVP 20) manages a plurality of storage apparatuses 10. The storage apparatus 10 includes a channel substrate 11, a drive substrate 13, a cache memory 14, and a processor substrate 12 as well as a sub-service processor (SSVP 18) that has an environment monitor unit 181 acquiring operation state information and a service processor monitoring unit (SVP monitoring unit 182) monitoring a SVP 20 and that is coupled to the processor substrate 12. The SVP 20 includes a communication control unit 203 coupled via a communication network 52 to the respective processor substrates 12 of the storage apparatuses 10 and a power control unit 205 coupled via a communication line to the SSVP 18 and powering off or on the SVP 20 according to a control signal sent from the SVP monitoring unit 182 via the communication line 55.