A semiconductor device according to an embodiment includes a SiC layer, an electrode electrically connected to the SiC layer and an impurity region provided between the SiC layer and the electrode. The impurity region includes first position and second position, the first position having highest concentration of an impurity in the impurity region, the highest concentration being not lower than 1×1020 cm−3 and not higher than 5×1022 cm−3, the second position having concentration of the impurity one digit lower than the highest concentration, the first position being between the electrode and the second position, a distance between the first position and the second position being 50 nm or shorter.