Stable receiving action is achieved with a receiver of simpler configuration.
When a human hand is held over the panel unit 201, the electric field in the vicinity of the human body is coupled to the sensor electrode 2122 of the coil sensor 212 from the receiving electrode 211 of the panel unit 201, and alternate current is generated at the sensor electrode 2122. This alternate current then induces a magnetic flux inside the central opening of the coil 2121 in proportion to the strength of the electric field in the vicinity of the human body. Depending on the changes in this magnetic flux, electric current passes through the coil 2121. The electric current passing through the coil 2121 is converted by the electric current detecting circuit 2124 of the coil sensor 212 to voltage signals and transmitted as received signals to the demodulator 22. As a result, the received signals corresponding to the electric field in the vicinity of the human body, namely the transmission signals applied by the transmitter 1 to the human body, are obtained.