A method for manufacturing a wiring board that has a rewiring layer on a surface thereof includes forming an insulating layer on a core substrate, forming a groove, in which a wiring layer of a circuit pattern is to be provided, on the insulating layer, forming a metal seed layer on an exposed face of the insulating layer on which the groove is formed, electrodepositing metal, which is to form the wiring layer, by plating to fill the groove with the metal to form a metal layer on the seed layer, machining the metal layer by a cutting tool to remove the metal layer up to a position not reaching the top of the insulating layer, and performing etching or a CMP process to expose the top of the insulating layer thereby to form the wiring layer in the groove and flatten an exposed face of the wiring layer.