A bump electrode, a dummy bump, and a heat-resistant polymer film, whose upper-surface heights are uniformed, are formed on each of a first silicon substrate and a second silicon substrate, and then, the first silicon substrate and the second silicon substrate are bonded to each other so that the bump electrodes formed on the respective substrates are electrically connected to each other. At this time, the dummy bump is arranged so as to be bonded to the heat-resistant polymer film on the silicon substrate opposed thereto, so that a semiconductor device having both of good electrical connection between the bump electrodes and bump protection performance obtained by a polymer film with high heat resistance and without voids can be achieved.