A wiring board has an insulating layer, a plurality of wiring layers formed in such a way as to be insulated from each other by the insulating layer, and a plurality of vias formed in the insulating layer to connect the wiring layers. Of the wiring layers, a surface wiring layer formed in one surface of the insulating layer include a first metal film exposed from the one surface and a second metal film embedded in the insulating layer and stacked on the first metal film. Edges of the first metal film project from edges of the second metal film in the direction in which the second metal film spreads. By designing the shape of the wiring layers embedded in the insulating layer in this manner, it is possible to obtain a highly reliable wiring board that can be effectively prevented from side etching in the manufacturing process and can adapt to miniaturization and highly dense packaging of wires.