A semiconductor device allowing a mounting of a semiconductor substrate with narrow electrode pad interval on an insulated circuit board while securing a favorable insulation characteristic and a manufacturing method thereof are obtained. The semiconductor device includes an electrode pad formed on a semiconductor substrate; a connecting underlying metal film connected to the electrode pad; a connecting conductor establishing electrical conduction between the connecting underlying metal film and a terminal electrode on an insulated circuit board; and non-conductive resin surrounding the connecting conductor and filling a gap between the substrate and the insulated circuit board. Here, the connecting underlying metal film is not covered by the connecting conductor at least in a peripheral region including an outer peripheral portion thereof