A printed wiring board includes an interlayer resin insulation layer having a penetrating hole for a via conductor, a conductive circuit formed on one surface of the interlayer resin insulation layer, a via conductor formed in the penetrating hole and having a protruding portion protruding from the other surface of the interlayer resin insulation layer, and a surface-treatment coating formed on the surface of the protruding portion of the via conductor. The via conductor is connected to the conductive circuit and has a first conductive layer formed on the side wall of the penetrating hole and a plated layer filling the penetrating hole.