To provide the difference current generation circuit of relatively simple circuitry operatable by low voltage power supply since the four pieces of transistors are vertically piled up, an operation when a power supply voltage is the low voltage of about 3V is difficult and an element number is large in the case that a circuit for generating a signal current is a double balanced mixer type in a conventional difference current generation circuit.

A current I8 flowing to a load resistor RL is indicated by the following expression. The expression is defined as I8=I6-I7I6-I5I4-I3= I0'-I0-I1I2. Also, since it is I3=I0 and I4=I0' when I1=I2=0 because of current mirror constitution, I9I0I0' is attained. Thus, the current I8 flowing to the load resistor RL becomes the difference current of the signal currents I1 and I2 and is taken out as a voltage centering a reference voltage VREF. This circuit is constituted by vertically piling up the three pieces of the transistors between a high potential side power supply terminal and a low potential side power supply terminal even when the double balanced mixer whose collector load resistor is resistors R1 and R2 is connected.