An interposer includes a substrate made of an inorganic material; a through wiring including conductors embedded in through holes; and an upper wiring and (or) a lower wiring. The through wiring, the upper wiring and the lower wiring are respectively formed on preliminary wiring patterns that are additionally simultaneously or sequentially formed on layers made of an insulating material applied to at least wiring forming parts of the substrate, and are formed with a metal mold itself used for forming the preliminary wiring patterns or layers made of a wiring material applied by a printing operation, a plating operation or a deposition on the preliminary wiring patterns formed on the layers of the insulating material by transferring a fine structure pattern of the metal mold.