PURPOSE: To provide a reference current source which operates with a low voltage by connecting a 1st current supply means to one electrode of a 1st transistor(TR) of a reference current source equipped with a current mirror circuit and a 2nd current supply means to the other electrode of the 1st TR.

CONSTITUTION: The collector of an NPN TR Q8 is connected to the collector of a PNP TR Q11 and a PNP TR Q12 is connected opposite to the PNP TR Q11. The collector of the PNP TR Q12 is connected to plural circuit blocks through plural current mirror circuits, the emitter of a PNP TR Q13 is connected to the base of the PNP TR Q12, and the base of the TR Q13 is connected to the collector of the PNP TR Q11. And, the collector of a NPN TR Q10 is connected to the emitter of the PNP TR Q11 and the collector of the PNP TR Q11 is connected to the collector of a TR Q8.