A wiring substrate includes a core layer, first conductor layers including a first inner conductor layer, a first outer conductor layer and a first intermediate conductor layer, second conductor layers including a second inner conductor layer, a second outer conductor layer and a second intermediate conductor layer, 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, and the first and/or second intermediate conductor layers has a second laminated structure including a metal foil layer and a plating film layer and includes a conductor pattern formed such that an upper surface of the conductor pattern has an edge portion forming an inclined portion inclined toward the core layer.