A semiconductor device of the present invention includes an output transistor connected between a power supply terminal and an output terminal; a detection transistor generating a detection current that is proportional to a current flowing through the output transistor; a detection voltage generation unit generating a detection voltage based on a detection current; a protection transistor drawing a current from a control terminal of the output transistor to the output terminal according to the detection voltage; and a limited current generation circuit that generates a limited current that is obtained by converting a limit setting current that sets a current flowing through the output transistor in a protection state according to a variation of a threshold voltage of the protection transistor and a variation of the detection voltage with respect to the detection current, and supplies the limited current to a first terminal of the protection transistor.