A via conductor can be formed directly on a through hole without using a special process for burying an inside of the through hole. A multilayer wiring substrate 1 has a buildup layer 3 and a buildup layer 4 constituted by laminating at least one insulation layer and at least one conductor layer; and a support substrate 21 supporting the buildup layers 3, 4 on an upper surface and a lower surface thereof, and is characterized in that the multilayer wiring substrate 1 has a through hole 24 formed to extend in a direction from an upper side to a lower side of the support substrate 21; a through hole conductor 25 formed in an inner circumferential surface of the through hole 24; a conductor layer 22 formed to cover an opening 241 of an upper side of the through hole 24 and electrically connected with the through hole conductor 25; and a conductor layer 23 formed around an opening 242 of a lower side of the through hole 24 without covering the opening 242 and electrically connected with the through hole conductor 25.