The converter device includes a rectification circuit that receives, as an input, AC power from an AC power supply, and performs full-wave rectification on the AC power received, a booster circuit that boosts an output voltage from the rectification circuit, a smoothing capacitor that smooths an output voltage from the booster circuit, and outputs a voltage smoothed, to the load, and a controller that controls the booster circuit. The booster circuit includes a plurality of booster sections each of which includes a reactor, a switching element, and a reverse-blocking diode. The controller maintains, in an ON state, the switching element included in at least one of the plurality of booster sections for a predetermined time period to determine the presence or absence of a fault of the booster section.