PURPOSE: To correctly divide voltage by connecting the gates of all four transistors of two pairs of complementary field effect transistors so that the bias voltage between the gate and the source of those transistors becomes equal.

CONSTITUTION: A P channel transistor 41 is matched with the Pchannel transistor 43, and an N channel transistor 42 is matched with the N channel transistor 44. In this case, output voltage to appear at an output terminal 46 is equal to the half of the voltage of a power source 45. Accordingly, in the case where the power source 45 is connected to a circuit 40, potential to appear at the output terminal 46 is +(V2)/2. As for the circuit 40, even if the size of +V4 is changed or drift arises, the voltage to appear at the output terminal 46 is +(V4)/2.