A switching circuit device includes high-side and low-side switching element circuits, and high-side and low-side drive circuits. The high-side switching element circuit includes a high-side switching element connected between an output terminal and a high-voltage terminal of a high voltage source. The low-side switching element circuit includes a low-side switching element connected between the output terminal and a reference potential terminal. The high-side drive circuit turns on the high-side switching element. The low-side drive circuit turns on the low-side switching element. The high-side drive circuit includes a bootstrap capacitor connected to a drive power source. The bootstrap capacitor is charged while the low-side switching element is ON. The high-side drive circuit applies a gate voltage to the high-side switching element while the low-side switching element is OFF. The gate voltage is defined by adding a voltage of the output terminal to a voltage of the bootstrap capacitor.