A voltage regulator is disclosed that includes first and second output transistors each outputting a current from the input terminal to the output terminal of the voltage regulator; and a control circuit part controlling the operations of the first and second output transistors to equalize a voltage proportional to an output voltage with a reference voltage. The control circuit part includes first and second error amplifier circuits each amplifying and outputting the difference between the proportional and reference voltages. The second error amplifier circuit consumes a smaller amount of current than the first error amplifier circuit. The control circuit part controls the output voltage by controlling the operations of the first and second output transistors using the first error amplifier circuit or controlling the operation of the second output transistor using the second error amplifier circuit in accordance with a control signal externally input to the control circuit part.