A semiconductor device includes: an n+ type of silicon carbide substrate, an n− type of layer, first trenches, a p type of region, a p+ type of region, an n+ type of region, a gate electrode, a source electrode, and a drain electrode. The semiconductor device may include a plurality of unit cells, wherein one of the plurality of unit cells may include a contact portion at which the source electrode and the p+ type of region contact each other, an outer portion disposed at upper and lower portions of the contact portion in a plan view, and a connection portion connecting the contact portion to the outer portion, a width between the first trenches horizontally adjacent in the plan view in the contact portion is equal to a width between the first trenches horizontally adjacent in the plan view in the outer portion, and a width between the first trenches horizontally adjacent in the plan view in the connection portion is less than a width between the first trenches horizontally adjacent in the plan view in the contact portion.