A choke coil includes a pair of E-shaped cores, first and second coil windings around central legs of the E-shaped cores, and an I-shaped core. Side legs of the pair of E-shaped cores are positioned face to face with each other with the I-shaped core intervening. There are gaps between the I-shaped core and each central leg. Electrical currents flow in the first and second coil windings in the same direction, and magnetic fluxes generated by each of the electrical currents are in opposite directions in the I-shaped core.