A first winding, a second winding, a fourth winding, and a fifth winding functioning as a transformer are wound around respective side legs of a three-leg core. Third windings functioning as a DC reactor are wound around a center leg. Winding directions of the first winding, the second winding, and the third windings are set so that magnetic fluxes generated by DC currents flowing through the respective windings merge in the same direction at the center leg, and winding directions of the fourth winding and the fifth winding are set so that magnetic fluxes generated by AC currents flowing through the respective windings cancel each other at the center leg. Thus, the transformer and the DC reactor are integrated using the three-leg core, whereby size reduction and loss reduction of the integrated magnetic component are achieved.