A printed wiring board includes resin insulation layers, conductive layers formed on the resin insulation layers respectively such that each of the conductive layers is formed on a surface of each of the resin insulation layers, and via conductors penetrating through the resin insulation layers respectively such that the via conductors are connecting the conductive layers through the resin insulation layers. Each of the resin insulation layers includes a modified resin layer formed by plasma treatment such that the modified resin layer is forming the surface of each of the resin insulation layers, each of the conducive layers includes a modified conductive layer formed by the plasma treatment such that the modified conductive layer is forming the surface of each of the conductive layers, and the modified resin layer has a surface modification different from a surface modification of the modified conductive layer.