The invention reduces outside dimensions of a semiconductor device mounted with a semiconductor die on an external connection medium and minimizes degradation of electrical characteristics of the semiconductor device. The semiconductor device of the invention having a semiconductor die and a lead frame with a plurality of lead terminals has following features. The semiconductor die has a plurality of pad electrodes formed on its front surface, at least one via hole penetrating the semiconductor die, a columnar electrode electrically connected with the pad electrode through the via hole, and a protrusion electrode electrically connected with the columnar electrode. At least one of the lead terminals of the lead frame is formed extending to a position connectable with the protrusion electrode, being connected with the protrusion electrode.