To eliminate an electrolytic capacitor that is needed between these stages when a filter circuit is cascaded to a subsequent stage of a demodulator circuit.

The non-linearity (DC offset included) of a demodulation output of a demodulator circuit 12 is absorbed by using a linear compensation circuit having the degree of freedom in a linear characteristic on the preceding stage of a filter circuit 17. Also, a compensating means absorbs the non-linearity of an FM demodulator circuit by setting an input dynamic range. Also, the compensating means adds a DC offsetting means to its inputting part and absorbs the non-linearity of the FM demodulator circuit.