A power converting apparatus makes reduction of power loss possible and operates in a two-phase mode. A power converting apparatus of the inventive concept includes I-shaped block cores, each being made of a magnetic material; and E-shaped cores, each being produced by combining two L-shaped magnetic materials to each of the I-shaped cores. In each of the E-shaped cores, the block core is defined as a central leg, the other two legs are defined as a first outside leg and a second outside leg, respectively, and a closed magnetic path is configured by two E-shaped cores combined such that one of respective central legs in the two E-shaped cores, one of respective first outside legs therein, and one of respective second outside legs therein are caused to face the other of the central legs, the other of the first outside legs, and the other of the second outside legs.