A printed wiring board includes an interlayer insulation layer, first pads positioned to mount a semiconductor element and forming a first pad group on the insulation layer, second pads forming a second pad group on the insulation layer and positioned along a peripheral portion of the first group, a first solder-resist layer formed on the insulation layer and having first openings exposing the first pads, respectively, and second openings exposing the second pads, respectively, conductive posts formed on the second pads through the second openings of the first solder-resist layer, respectively, and a second solder-resist layer formed on the first solder-resist layer and having a third opening exposing the first pads and fourth openings exposing surfaces of the posts, respectively. The second openings have a diameter greater than a diameter of the posts, and the second solder-resist layer is filling gaps formed between the second openings and the posts.