The storage virtualization switch is capable of correctly designating a virtual target when a host computer accesses the virtual target. A dummy virtual target, which corresponds to a virtual target, is put into an effective state after the virtual target is put into the ineffective state when the virtual target is put into the ineffective state, and the virtual target is put into an effective state after the dummy virtual target, which corresponds to the virtual target, is put into the ineffective state when the virtual target is put into the effective state.