A wiring substrate includes a first outermost conductor layer, a first outermost insulating layer covering the first conductor layer, a second outermost conductor layer formed on opposite side of the first conductor layer, and a second outermost insulating layer covering the second conductor layer. The first insulating layer has first openings such that the first openings are exposing first conductor pads including portions of the first conductor layer, the second insulating layer has second openings such that the second openings are exposing second conductor pads including portions of the second conductor layer, each of the first conductor pads has a first plating layer recessed with respect to outer surface of the first insulating layer, and each of the second conductor pads has a second plating layer formed flush with outer surface of the second insulating layer or having bump shape protruding from the outer surface of the second insulating layer.