PURPOSE: To select automatically a prescribed signal with good operability, by stopping the change in a control voltage only when the receiving of a TV broadcast signal having a signal of prescribed mode of sound multiplex broadcast is discriminated by detecting its pilot signal.

CONSTITUTION: A receiving frequency of an electronic tuner 2 is changed sequentially by changing sequentially the control voltage with a channel selection circuit 10. Then, the receiving of the TV broadcast signal is confirmed with a detecting signal detecting the coincidence of the video image IF from a video IF amplifier detecting circuit 3 and a coincidence circuit between a horizontal synchronizing signal from a horizontal/vertical deflection cicuit 11 and a flyback pulse. Further, a detecting signal of the pilot signal such as a sound multiplex subcarrier or the like from a sound multiplex signal demodulation/amplifier circuit 7 is monitored to discriminate whether or not the TV broadcast is a sound multiplex broadcast sgnal of the desired mode. As a result, only when the receiving of the sound multiplex broadcast signal of the prescribed mode is discriminated, the change in the control voltage applied from the circuit 10 to the tuner 2 is stopped so as to receive continuously the broadcast signal.