PURPOSE: To suppress the production of pulsative noise by providing 1st and 2nd FM detectors, two frequency converters, a band pass filter and an adder adding a demodulation signal obtained as an output of the 2nd FM detector and an output signal of the 1st FM detector so as to make the pass band narrower.

CONSTITUTION: An output obtained by an FM detection section 1 is subject to FM modulation by an FM modulator 7 and the output and input are led to a mixer to decrease the frequency deviation of the input FM signal. Moreover, the output of a mixer 8 is FM-detected by an FM detection section 11 and the said output and the output of the FM detection section 1 are summed by the adder 15. In this case, since the output of the mixer 8 has a narrower frequency deviation, the pass band width of a BPF 12 is made narrow and the noise in the output of the BPF 12 is decreased, then the production of pulsative noise is suppressed.