A frequency converter circuit used for a receiver for satellite broadcast. Local oscillation signals are supplied from a single local oscillation circuit (8) to mixer circuits (11a,11 b) of electric signal processing circuits (4, 5) of two or more systems, and a mixer diode (27) of each ofthe mixercircuits (11a, 11 b) is biased with a direct current. Even the mixer diode (27) of the signal processing circuit of the system that is not in operation is biased with the direct current at all times, presenting advantage in regard to stable operation, small size, light weight, and low cost.