An injection molded article is provided with: a flat molded resin body that has a flat rectangular parallelepiped shape and is formed from an injection molded resin; and a base sheet affixed to the surface of the molded resin body. The base sheet has formed therein a first conductive layer on a first surface and a through hole passing through from the first surface to a second surface. The through hole is filled with a conductive material, and a second conductive layer is formed so as to be electrically connected with the first conductive layer via the conductive material with which the through hole is filled. In addition, a sealing material is formed on the first conductive layer so as to cover the through hole. The molded resin body is fixed together with the first surface side of the base sheet so as to cover the sealing material.