PURPOSE: To prevent a stop caused by the reception of a spectrum generated owing to intermodulation disturbance during automatic channel selection by employing a deciding method which discriminates an actual broadcast signal from the spectrum generated owing to the intermodulation disturbance.

CONSTITUTION: A level detector 16 measures levels of an antenna input signal before and after a gain control means 24 which provides constant-amount attenuation operates; the detected broadcast signal is judged as the actual broadcast signal when the difference between measured values satisfies an inequality in a figure or as the spectrum component due to the intermodulation disturbance when not. In the inequality, 1<α<3. Consequently, a stop caused by the detection of the spectrum component generated owing to the intermodulation disturbance is prevented during automatic channel selection.