To freely set a temp. coefficient by using a specific formula by reversing the control signal formed by a control signal forming circuit to add the same to the detection signal formed by a temp. detection circuit to obtain a temp. detection signal.

An NPN transistor Q26 is constituted so that the emitter thereof is connected to the contact (a) of a constant current source 35 and a resistor R22 and the base thereof is connected to the connection point of the collector of a transistor Q24 and the emitter of an NPN transistor Q27 and controls the current supplied to resistors R22, R23, R24 from the constent current source 35 when the band gap Zener voltage ΔVBE generated in a resistor 23 lowers. The change (Vs31/ T) of the output detection voltacje to the temp. of a temp. detection circuit 31 can be made larger than the change of the output detection voltage to the temp. of a conventional temp. detection circuit 1, and the change of the output detection and the change of the detection voltage to the temp. of the circuit 31 can be freely set on the basis of the ratio of the resistors R21, R23 as shown by the formula.