A gate driver, which drives an N-channel type transistor connected between an application terminal of an input voltage and an application terminal of a switch voltage, includes a capacitor circuit connected between an application terminal of a boot voltage higher than the switch voltage by a voltage between both ends of the boot capacitor and the application terminal of the switch voltage, and a timing control circuit that charges an input gate capacitance of the transistor with the boot voltage after precharging the same with the input voltage during turn-on transition of the transistor, and decreases capacitance value of the capacitor circuit after the turn-on transition of the transistor.