A DC--DC converter switches a semiconductor switch device for converting a DC voltage to a certain level and supplies the converted DC voltage to a load. The DC--DC converter is configured to be able to switch between a first feedback control mode and a second feedback control mode. The DC--DC converter selects the second feedback control mode when a load current flowing through the load is below a predetermined value. The DC--DC converter selects the first feedback control mode when a level of the DC voltage supplied to the load changes irrespective of a value of the load current.