A semiconductor device having a semiconductor substrate that includes a first-conductivity-type substrate and a first-conductivity-type epitaxial layer, and a plurality of trenches reaching a predetermined depth from a main surface of the semiconductor substrate to terminate in the first-conductivity-type epitaxial layer. The semiconductor substrate includes a hydrogen-donor introduced part, of which a concentration of a hydrogen donor is greatest at a depth position that is separate from bottoms of the trenches by a distance at least two times of the depth of the trenches. The impurity concentration of an impurity dopant of the first-conductivity-type substrate being lower than that of the first-conductivity-type epitaxial layer. A difference between a first resistivity, corresponding to a total impurity concentration of the impurity dopant and the hydrogen donor of the first-conductivity-type substrate, and a second resistivity, corresponding to the impurity concentration of the impurity dopant of the first-conductivity-type epitaxial layer, is at most 20%.