PURPOSE: To obtain a high-gain mixer circuit which has mutually independent input matching circuits, by connecting the drain of the 2nd FET to the source or gate of the 3rd FET in the mixer circuit used for an SHF band, etc.

CONSTITUTION: An FET1 is constituted by connecting the drains of an FET1a and an FET1b, and the source of an FET1c common. An input signal is supplied to the terminal 2a of a circuit and led to the gate G1 of the FET1 through a strip line 17 constituting a matching stub. A local oscillation signal is supplied to the terminal 3a and then applied to the gate G2 of the FET1 through a strip line 18 constituting a matching stub. In addition, a drain voltage Vdd is applied to the drain D3 of the FET1 through an inductance L and a strip line filter 21, and an IF signal is let out through a DC cutting capacitor C6. The sources S1 and S2 of the FET1 and its gate G3 are grounded in terms of high frequency. The gate G3 of the FET1 may be connected in common.