The voltage regulator includes a resistor circuit that switches between a first state and a second state according to the comparison result signal. In the first state, a resistance between a second end of a first controlling transistor and a fixed potential is set at a first resistance, and a second end of a second controlling transistor and the fixed potential are disconnected from each other. In the second state, the second end of the first controlling transistor and the fixed potential are disconnected from each other, and a resistance between the second end of the second controlling transistor and the fixed potential is set at a second resistance.