To provide a load current differential detection/control circuit capable of breaking a current at high speed only when a load current is rapidly increased.

This circuit is composed of at least first, second and third semiconductor devices QA, QB and QC, a first comparator CMP 1 connecting an input terminal to the first and third semiconductor devices QA and QC, a resistor R22 connected to the output terminal of the first comparator CMP 1, a capacitor C23 connected to this resistor R22, a fifth semiconductor device Q21 connecting a first main electrode to the third semiconductor device QC, connecting a control electrode to the resistor R22 and connecting a second ground resistor R24 to a second main electrode and a fourth semiconductor device Q22 connecting a first main electrode to the second semiconductor device QB and connecting a control electrode to the second main electrode of the fifth semiconductor device Q21. Only when time differential di/dt of an abnormal current is greater than a prescribed value, a current vibration is generated by turning on/off the first semiconductor device QA.