A semiconductor device includes a front surface electrode, a back surface electrode and a semiconductor substrate in which an IGBT and a diode are formed. An outer peripheral back surface p-type region, an outer peripheral back surface n-type region, and an outer peripheral low concentration n-type region are formed in an outer peripheral region. The outer peripheral back surface n-type region is formed on an end surface side of the semiconductor substrate with respect to the outer peripheral back surface p-type region. The outer peripheral low concentration n-type region separates the outer peripheral back surface p-type region and the outer peripheral back surface n-type region from a contact outer peripheral edge p-type region. A p-type impurity concentration in the outer peripheral back surface p-type region decreases toward the end surface. An n-type impurity concentration in the outer peripheral back surface n-type region increases toward the end surface.