A storage network system (1) includes a sever (100), a storage device (300), and a management server (400). A device control processor (120) of the server (100) includes an authentication ID management unit (130). The authentication ID management unit (130) has an authentication ID management table (131) which manages an authentication ID held at present. A port controller (310) of the storage device (300) includes an access control unit (320). The access control unit (320) is provided with an access control table (321) indicative of a criterion which permits an access from the server (100). An access management unit (410) of the management server (400) has an operation schedule table (420) indicative of an operation schedule of operations from the server (100) to the storage device (300), and an access management table (421) which manages an operation permitted at present.