To improve both receiving characteristic and noise resistance of an AM receiver in a weak electric field.

A carrier signal generation circuit 22 generates an orthogonal carrier signal SQD from an AM signal SAM, and an addition circuit 21 adds together both signals SAM and SQD. A limiter 23 sets the amplitude of an output signal SWA of the circuit 21 at a fixed level, and a phase detection circuit 24 detects the phase of the output signal of the limiter 23. A correction circuit 25 corrects the distortion of output signal Sθ of the circuit 24. The circuit 25 generates a signal from the output signal itself of the limiter 23 to perform its distortion correcting operation. The output signal G of the circuit 25 is taken out as the AM detection output of the signal SAM.