PURPOSE: In a device for operating an electric appliance on a door by a manipulator on another prescribed door, to dispense with electric wires for signal transmission and heighten reliability, by transmitting a magnetic signal between each door and the body of a vehicle.

CONSTITUTION: When one of the switches 2aW2d of a manipulator 1 mounted on a door 5 at the driver's seat of an automobile is operated as all the doors of the automobile are closed, the operated state of the switch is detected by a transmission circuit 4 and converted into a time-series signal to drive an electromagnetic transducer 3 to send out a magnetic signal, which is received by a magnetoelectric transducer 6 on the body 9 of the automobile and converted into an electric signal. The electric signal is amplified at 7 and then applied to an electromagnetic transducer 8, which converts the electric signal into a magnetic signal. The magnetic signal is received by a magnetoelectric transducer 10 on the door at a seat next to the driver's seat. The output signal of the transducer 10 is decoded by a control circuit 11, whose output signal is applied to the actuator of a power-driven window or the like.