PURPOSE: To obtain a filter circuit where the transfer function does not depend on the absolute temperature, in a filter circuit for which a current bias is applied.

CONSTITUTION: A filter circuit 8 has a prescribed transfer function expressed by including thermal voltage VT which is proportional to the absolute temperature and a current bias is applied to the circuit 8 by a bias circuit part 9. The bias circuit part 9 has a thermal voltage compensation circuit 10 and the part 9 applies a current bias for a filter circuit part 3 so as to cancel thermal voltage VT in the transfer function. Thus, the transfer function does not depend on the absolute temperature.