A DC-DC converter including a first inductor connected between a second end of a first MOS transistor and an output terminal, a second inductor connected between a second end of a third MOS transistor and the output terminal, a first capacitor connected between the second MOS transistor and the third MOS transistor, a second capacitor connected between the fourth MOS transistor and the first MOS transistor and a third capacitor connected between the first MOS transistor and the third MOS transistor. Also included in the converter is a first resistor connected to a gate of the second MOS transistor, a second resistor connected to a gate of the fourth MOS transistor, and a first bias adjustment circuit which compares the output voltage with a preset first reference voltage and applies a first bias voltage to the resistors to make the output voltage equal to the first reference voltage.