To provide a print system with which power consumption of a printer connected on a network can be more efficiently controlled.

A print server 20 detects the log-out of a work station 10 or detects the disconnection of a logic session between the print server 20 and the work station 10 and changes a power unit 34 of a printer 30 from an ordinary mode to a energy save mode. Thus, the printer 30 to be switched to the energy saving mode after the elapse of a fixed time can be changed to the energy save mode without waiting its own function and the power consumption of the printer 30 can be efficiently managed.