A power window system includes: an open/close switch that is provided to each of a plurality of vehicle seats for issuing an open/close instruction to the corresponding seat windows; a control device for controlling the open/close operation of the seat windows based on the operation of the open/close switch, and is configured by as many control sections as the vehicle seats with a one-to-one relationship therebetween, i.e., a master controller and a plurality of sub controllers; and a communications unit for carrying out communications between the control section at a driver seat and the control sections at the remaining seats. The sub controllers at the seats other than the driver seat are each provided with an operation command section, operating when the communications is not normally available with the master controller at the driver seat even if a close signal is issued from the open/close switches. In such a case, the operation command section forwards a command to a motor control section to move the seat window in a direction to close it by a predetermined amount.