A first conductive member made of metal is provided over a first wiring substrate, which is a mounting substrate in the lower tier, a through hole is provided in a second wiring substrate, which is a mounting substrate in the upper tier, at a position corresponding to the first conductive member in a plan view, and a wiring is exposed at the sidewall of the through hole. The first conductive member is inserted into the through hole on the corresponding first wiring substrate side and the first wiring substrate and the second wiring substrate are electrically coupled by filling the through hole with a second conductive member. an electrode pad that is electrically coupled to the second conductive member and over which a semiconductor member in the upper tier is mounted is formed on the main surface side of the second wiring substrate.