Module and method for manufacturing the module

A module includes an insulating layer, a ring-shaped magnetic core built in the insulating layer, a coil electrode disposed in the insulating layer so as to spirally wind around the magnetic core, and heat-dissipating metal bodies respectively disposed outside and inside the magnetic core within the insulating layer. Building the magnetic core into the insulating layer as described above eliminates the need to provide the principal face of the insulating layer with a large mounting area for mounting a coil formed by the magnetic core and the coil electrode. This allows the area of the principal face of the insulating layer to be reduced to achieve miniaturization of the module. The presence of the heat-dissipating metal bodies respectively disposed outside and inside the magnetic core within the insulating layer improves dissipation of the heat generated from the coil.