PURPOSE: To keep an output current stable against a power supply fluctuation and a temperature change in a load drive circuit employing a differential pair of complementary MOSFETs.

CONSTITUTION: The drive circuit is provided with two sets of differential pairs 31, 32 supplied from the same current source transistor(TR) 33 and whose gates receive the same input, the one differential pair 31 drives a load Ro and the other differential pair 32 supplies a monitor current Im proportional to the load drive current. Then the gate of the current source TR 33 is controlled via a negative feedback loop L so that the monitor current Im is constant independently of DC level fluctuation. Furthermore, the drive circuit is also provided with a monitor circuit 6 controlled by the same gate voltage VG as that of the current source TR 33 and supplying a current proportional to the output current and the negative feedback loop L is used to control the gate voltage VG so that the current Im of the monitor circuit is made constant.