A printed wiring board including an insulation layer made of a resin material and having first and second surfaces, the insulation layer having an opening portion opened on the second surface, a conductive circuit having first and second surfaces, the conductive circuit being embedded in the insulation layer such that the first surface of the conductive circuit is formed flush with the first surface of the insulation layer and that the second surface of the conductive circuit is exposed through the opening portion of the insulation layer, a first surface-treatment film formed on the conductive circuit and facing the first surface of the conductive circuit, and a second surface-treatment film formed on the conductive circuit and facing the second surface of the conductive circuit and in the opening portion of the insulation layer.