A wiring board includes a first insulating layer made of a single layer of non-photosensitive resin including a reinforcing member, a center position of the reinforcing member being positioned on a side toward a first surface with respect to a center of the first insulating layer in a thickness direction; a layered structure of a wiring layer and an insulating layer, stacked on the first surface of the first insulating layer; a through wiring provided to penetrate the first insulating layer, the through wiring and the first insulating layer forming a first concave portion at a second surface of the first insulating layer, in which the second end surface of the through wiring is exposed; and a pad for external connection formed at the second surface of the first insulating layer at a position corresponding to the through wiring and having a second concave portion.