A wiring substrate includes a heat sink to dissipate heat generated in an electronic part mounted in an electronic part loading area on a principal surface of the wiring substrate, an encapsulation resin to cover the heat sink, an inner connection terminal having an end face electrically connected to an electrode of the electronic part, and an outer connection terminal electrically connected to the inner connection terminal via a wiring and having an end face for inputting and outputting of a signal with an external device. The encapsulation resin is arranged to cover a part of the wiring, the inner connection terminal except the end face, and the outer connection terminal except the end face. A surface of the heat sink, the end face of the inner connection terminal, and the end face of the outer connection terminal are flush with and exposed to the principal surface.