To provide a receiver 31 for enabling frequency conversion for operat ing an AGC operation at a high speed and to deal with a strong input in the case of performing the AGC operation for keeping an input signal level to a demodulating circuit 38 constant.

Two stages of IF amplifiers 36 and 37 are arranged, so as to perform wave detection in the level of an IF signal from the IF amplifier 37 by a level detection circuit 40, the gain of the IF amplifier 37 is finely controlled by the wave detection output, and then, correspondence is promptly established to a very small level change, which occurs in a comparatively short time. In the meantime, a comparing circuit 41 compares the wave detection output with a reference level, and the gains of a high-frequency variable gain amplifier 33 and the IF amplifier 36 are controlled, in response to the comparison result. Then a large level change over a comparatively long time can be tracked, even if time delay occurs in control. Then the input signal level of each part is kept at a proper level without saturation.