An electromagnetic induction device, and a power supply apparatus and a display apparatus having the same are disclosed, the electromagnetic induction device comprising: a substrate layer comprising at least one substrate configured to be laid one upon another and a thin-film coil pattern, which is formed on at least one of both surfaces of the substrate and through which an electric current of a signal flows, the at least one substrate having an opening provided at an inner area of the thin-film coil pattern; a core configured to have a shape corresponding to a circulation path of magnetic flux generated by change in an electric current flowing in the thin-film coil pattern, and arranged to penetrate the inner area of the thin-film coil pattern through the opening of the substrate layer; and a heat dissipation layer disposed on one surface of the substrate, the heat dissipation layer configured to dissipate heat from at least one of the substrate layer and the core.The disclosed configuration addresses the problem of heat dissipation in a thin flat-plate structure.