To form a semiconductor device, a through electrode is formed in a semiconductor die, and a dielectric layer is then formed to cover the through electrode. The dielectric layer has an opening by being partially etched to allow the through electrode to protrude to the outside, or has a thickness thinner overall so as to allow the through electrode to protrude to the outside. Subsequently, a conductive pad is formed on the through electrode protruding to the outside through the dielectric layer by using an electroless plating method.