A wiring substrate includes a core layer, first conductor layers including first inner, outer and intermediate conductor layers, second conductor layers including second inner, outer and intermediate conductor layers, and interlayer insulating layers interposed between the first conductor layers and between the second conductor layers. The first and/or second inner conductor layers has a first laminated structure including a metal foil layer and a plating film layer, the first and/or second outer conductor layers has the first laminated structure, the first and/or second intermediate conductor layers has a second laminated structure including a metal foil layer and a plating film layer, and the first and second laminated structures are formed such that a surface of the second laminated structure on a side away from the core layer has unevenness smaller than unevenness of a surface of the first laminated structure on a side away from the core layer.