PURPOSE: To decrease the fluctuation in a bias current due to a temperature change by compensating a temperature dependency of a current for form a bias voltage with a reference voltage having a positive temperature characteristic outputted from a voltage generating circuit.

CONSTITUTION: A voltage generating circuit 6 applies a reference voltage Vg12 having a positive temperature characteristic to a MOSFET Q12 of a current generating circuit 5. A current Is12 flows from the current mirror circuit comprising MOSFETs Q13, Q14 of the circuit 5 to MOSFETs Q15, Q16 having an equal threshold voltage and of two stages in series. Moreover, the current Is11 depends on the size of a current source Q11 and a voltage Vg12 and the size of the MOSFETs Q15, Q16 is multiplied by a multiple of four of that of the MOSFET Q12 and the current is independently of a power supply voltage and the threshold voltage. Thus, the temperature dependency of the bias current is decreased and the fluctuation in the bias current due to a temperature change is decreased.