PURPOSE: To obtain a balanced mixer circuit by providing a tap to a parallel resonance coil being a component of an RF tank circuit and connecting the intermediate tap to ground so as to inject a local signal to a balanced output terminal of the tank circuit via a capacitor respectively.

CONSTITUTION: A tap CT is provided to a coil L1 of an RF tank circuit 1 comprising the coil L1 and a capacitor C2, the tap CT connects to ground and both terminals of the coil L1 are used as balanced output terminals O1, O2 of the RF tank circuit via capacitors C8, C9. A local signal L0 is injected from a local signal oscillator 3 via capacitors C10, C11 to the balanced output terminals O1, O2. An impedance means 4 showing a low impedance with respect to an IF signal and showing a high impedance with respect to the local signal is divided into coils L5, L6 and consists of a resonance circuit with a distributed capacitance Co in FETs Q1, Q2 and the IF signal is extracted by a tuning circuit 5.