A wiring board includes a base substrate, a semiconductor element embedded in the substrate and having active and non-active surfaces such that the semiconductor has a terminal on the active surface, a first build-up layer including an insulating layer and first conductor pads such that the first conductor pads have exposed surfaces exposed from a surface of the insulating layer on the opposite side with respect to the substrate, and a second build-up layer including an insulating layer and second conductor pads such that the second conductor pads have exposed surfaces exposed from a surface of the insulating layer on the opposite side with respect to the substrate. The insulating layer in the first build-up includes resin material and reinforcing material, the insulating layer in the second build-up includes resin material and reinforcing material, and the first conductor pads is embedded in the insulating layer in the first build-up.