A defibrillator according to one embodiment of the present invention comprises: a high voltage capacitor charged through a battery power source； a ladder bridge circuit connected to one end of the high voltage capacitor； a control unit for controlling an on/off operation of switching elements constituting the ladder bridge circuit, wherein the ladder bridge circuit comprises: a first circuit unit and a second circuit unit, one ends of which are connected to one end of the high voltage capacitor and which are connected in parallel to each other； and a third circuit unit connected in series to the other ends of the first circuit unit and the second circuit unit, wherein the first circuit unit comprises a first switching element having one end connected to the high voltage capacitor and a second switching element connected in series to the other end of the first switching element； the second circuit unit comprises a third switching unit connected to the high voltage capacitor and a fourth switching element connected in series to the other end of the third switching element； and the third circuit unit comprises a fifth switching element and a sixth switching element, one ends of which are connected in parallel to the other ends of the first circuit unit and the second circuit unit.
