A method for manufacturing printed wiring board includes irradiating laser on first surface of substrate such that first opening portion having first opening on the first surface and inner diameter decreasing toward the second surface is formed, irradiating laser on second surface of the substrate such that second opening portion having second opening on the second surface and inner diameter decreasing toward the first surface is formed and that the second portion joins the first portion and forms a penetrating hole penetrating through the substrate, forming a first circuit on the first surface, forming a second circuit on the second surface, and filling the hole with plating such that a through-hole conductor which electrically connects the first and second circuits is formed. The first opening has diameter same as or greater than diameter of the second opening, and the first portion has depth less than depth of the second portion.