A control circuit includes a drive circuit which applies a drive voltage to a semiconductor device having an overheating protection function according to an externally supplied signal; and a current detecting circuit which outputs a detection signal when a drive current flowing through the semiconductor device exceeds a predetermined threshold current. The semiconductor device incorporates a semiconductor element, a temperature detecting circuit for detecting temperature increase of a chip, and an interrupting circuit for interrupting an input to the semiconductor element according to a detection output of the temperature detecting circuit. The drive circuit turns off the semiconductor element and changes the drive voltage to a predetermined voltage so that the drive current exceeds the threshold current when the interrupting circuit interrupts an input to the semiconductor element, and keeps the drive voltage at the predetermined voltage while the detection signal is output from the current detecting circuit.