A printed wiring board includes an insulating layer, a first conductor layer embedded into a first surface of the insulating layer and including connecting portions to connect an electronic component, a second conductor layer projecting from a second surface of the insulating layer, a solder resist layer covering the first conductor layer and having an opening structure exposing the connecting portions, a barrier metal layer formed on the connecting portions such that the barrier layer is projecting from the first surface of the insulating layer, and metal posts formed on the barrier layer such that the metal posts are positioned on the connecting portions, respectively. Each metal post has width which is greater than width of a respective connecting portion, and the barrier metal layer includes a metal material which is different from a metal material forming the metal posts and a metal material forming the first conductor layer.