A semiconductor device 1 includes an output MOS transistor M2, a sense MOS transistor M3, a voltage conversion circuit 20 that converts a sense current of the sense MOS transistor M3 into a sense voltage, and control MOS transistor M10 having a gate and a source which receive the sense voltage therebetween and a drain connected to a gate of the output MOS transistor M2. The voltage conversion circuit 20 includes a first MOS transistor M21 diode-connected and a second MOS transistor M22 connected in series to the first transistor M21. A gate of the second transistor M22 is connected to a node between a gate control circuit 6 and a resistor R5 which is connected to the gate of the output MOS transistor M2. A variation in threshold voltage caused by characteristic variation of the control MOS transistor M10 causes a variation in output current limiting value, but the threshold voltage of the first MOS transistor M21 diode-connected varies similarly, whereby the variation in threshold voltage caused by characteristic variation of the control MOS transistor M10 is cancelled. As a result, the variation in output current limiting value is suppressed.