A semiconductor device capable of preventing deterioration of a transistor caused by a flow of an overcurrent is provided. According to an embodiment, a semiconductor chip includes a first transistor provided between a high-potential side voltage terminal to which a constant voltage generated by reducing a power-supply voltage is supplied and an output terminal, a second transistor provided between a low-potential side voltage terminal to which a ground voltage is supplied and the output terminal, a control circuit controlling turning-on/off of the first and second transistors, a boosting circuit boosting the power-supply voltage by using a voltage of the output terminal to generate an output voltage, and an overvoltage detection circuit detecting an overvoltage of a power-supply line that couples the high-potential side voltage terminal and the first transistor to each other. The control circuit performs control to turn off the second transistor, when the overvoltage has been detected.