A printed wiring board including an interlayer resin insulation layer, a pad formed on the interlayer resin insulation layer and for mounting an electronic component, a solder-resist layer formed on the interlayer resin insulation layer and the pad and having an opening portion over the pad, and a coating layer formed on the pad and exposed through the opening portion of the solder-resist layer. The solder-resist layer has a protruding portion protruding toward the inside of the opening portion in a bottom portion of the opening portion, and the protruding portion of the solder-resist layer has a flat surface in an end portion of the protruding portion.