A wiring board includes a first wiring layer formed on one surface of a core layer, a first insulating layer formed on the one surface of the core layer so as to cover the first wiring layer, a via wiring embedded in the first insulating layer, a second wiring layer formed on a first surface of the first insulating layer, and a second insulating layer thinner than the first insulating layer formed on the first surface of the first insulating layer so as to cover the second wiring layer. The first wiring layer comprises a pad and a plane layer provided around the pad. One end surface of the via wiring is exposed from the first surface of the first insulating layer and directly bonded to the second wiring layer. The other end surface of the via wiring is directly bonded to the pad in the first insulating layer.