A method for manufacturing a multilayer wiring substrate having: a step (1) for providing, using a conformal method or direct laser method, an opening for a via hole extending from a metallic foil for forming an upper layer wiring line to an inner layer wiring line, a protruding portion of the metallic foil for forming the upper layer wiring line formed in the aperture portion of the opening for a via hole, and a lower space formed between the protruding portion of the metallic foil and the inner wall of the opening for a via hole; and a step (2) for filling the opening for a via hole by forming an electrolytic filler plating layer in the opening for a via hole and on the metallic foil for the upper layer wiring line. The filling of the opening for a via hole by forming the electrolytic filler plating layer during step (2) is performed by first reducing the current density of electrolytic filler plating during electrolytic filler plating, and then increasing the current density.