According to a single-stage interleaved software switching converter, power factor is controlled and battery charging and current are integrally controlled on the basis of a PFC circuit of a single-stage interleaving type so that efficiency of a charging device is enhanced and the cost is reduced. Further, it is possible to remove harmful electromagnetic radiation; enhance power density and durability by using a film-type capacitor instead of the conventional electrolytic capacitor; reduce switching loss by soft switching operation and to reduce the volume of a filter unit; design magnetizing current to be small by removing a low-frequency component of a transformer and to reduce the volume; and perform high-power charging according to the number of windings of the transformer.