The wiring board comprises a plate-shaped conductive core material 10 with a through-hole 12 formed in, an insulation layer 14 formed on the surface of the conductive core material 10 and on the inside wall of the through-hole 12, a resin 18 buried in the through-hole 12 with the insulation layer 14 formed in, wirings 22a, 22b formed on the upper surface and the undersurface of the conductive core material 10 with the insulation layer 14 formed on, and an wiring 22d formed in the through-hole 20 formed in the resin 18 and electrically connected to the wirings 22a, 22b.