A DC-DC converter that includes: a high-side switch; a low-side switch; an inductor; an output capacitor; and a controller. In the DC-DC converter, the controller includes: a pre-charge circuit that charges the output capacitor; a negative current detection circuit that outputs a negative current detection signal indicating that current flowing from the inductor to the low-side switch has reached a predetermined value; and a control circuit that performs a switching operation that alternately turns on the high-side switch and the low-side switch, and the control circuit starts the switching operation by turning on the low-side switch, and turns off the low-side switch after receiving the negative current detection signal.