To obtain a communication apparatus which can be operated without changing over a communication function and a radar function by a method wherein the factor of a radar signal is superposed on an RF signal which executes a communication operation.

A demodulation circuit 4 wherein a receiving signal, at a first frequency, on which an audio signal is superposed is received by an antenna 1 so as to be fetched and demodulated by a directional coupler 3 through a branching filter 2 and a voice is output is provided. A loudspeaker 5 is provided. A modulation signal 11 or the like by which the receiving signal is delayed by a prescribed time so as to be superposed on an RF signal and so as to be modulated by the audio signal and which transmits the receiving signal from the antenna 1 through the branching filter 2 as a transmitting signal at a second frequency is provided. A distance detection circuit 7 which fetches the receiving signal by a directional coupler 6 and which detects a distance up to a communication parner apparatus by detecting the time delay portion of a space between the transmitting signal and the receiving signal is provided. Thereby, a communication function and a radar function can be operated simultaneously, and a transmitting operation and a receiving operation can be executed simultaneously without changing over the communication function and the radar function and without changing over the transmitting operation and the receiving operation.