Next, as shown in FIG. 3, by laser processing in which laser beam irradiation is performed, a first groove 24 is formed in the passivation film 7 and the four layers of low-dielectric film 4 in the area including the dicing street 22 and both sides of the dicing street 22 within the opening 23 in the upper-layer protective film 95 The first groove 24 is formed having a width narrower than that of