A semiconductor device includes a base region of second conductivity type formed on a drift layer of first conductivity type, a source region of first conductivity type located in the base region, a trench passing through the base region and the source region and dividing cell regions in plan view, a protective diffusion layer of second conductivity type disposed on a bottom of the trench, a gate electrode embedded in the trench with a gate insulating film therebetween, a source electrode electrically connected to the source region, and a protective contact region disposed at each of positions of three or more cell regions and connecting the protective diffusion layer and the source electrode to each other. The protective contact regions are disposed such that a triangle whose vertices are centers of three protective contact regions located closest to one another is an acute triangle.