A semiconductor device comprising: a semiconductor substrate containing oxygen, wherein an oxygen concentration distribution in a depth direction of the semiconductor substrate has a high oxygen concentration part on an upper surface-side of the semiconductor substrate, where an oxygen concentration is higher than in a lower surface of the semiconductor substrate, wherein the upper surface-side of the semiconductor substrate is the portion of the semiconductor substrate located between an upper surface and a center (Dc) of the semiconductor substrate in the depth direction, wherein the high oxygen concentration part has a concentration peak in the oxygen concentration distribution, wherein the semiconductor substrate is provided with an active portion and an edge termination structure portion surrounding the active portion, and the active portion is provided with a transistor portion and a diode portion, wherein the transistor portion and the diode portion are alternately arranged in an arrangement direction, wherein an upper surface-side lifetime control region is provided continuously in the arrangement direction in the diode portion and in a part of the transistor portion in contact with the diode portion, wherein the upper surface-side lifetime control region is a region including crystal defects, wherein a crystal defect density distribution of said crystal defects in the depth direction of the semiconductor substrate has an upper surface-side density peak on the upper surface-side of the semiconductor substrate, and the concentration peak is arranged between the upper surface-side density peak and the upper surface of the semiconductor substrate. a semiconductor substrate containing oxygen, wherein an oxygen concentration distribution in a depth direction of the semiconductor substrate has a high oxygen concentration part on an upper surface-side of the semiconductor substrate, where an oxygen concentration is higher than in a lower surface of the semiconductor substrate, wherein the upper surface-side of the semiconductor substrate is the portion of the semiconductor substrate located between an upper surface and a center (Dc) of the semiconductor substrate in the depth direction, wherein the high oxygen concentration part has a concentration peak in the oxygen concentration distribution, wherein the semiconductor substrate is provided with an active portion and an edge termination structure portion surrounding the active portion, and the active portion is provided with a transistor portion and a diode portion, wherein the transistor portion and the diode portion are alternately arranged in an arrangement direction, wherein an upper surface-side lifetime control region is provided continuously in the arrangement direction in the diode portion and in a part of the transistor portion in contact with the diode portion, wherein the upper surface-side lifetime control region is a region including crystal defects, wherein a crystal defect density distribution of said crystal defects in the depth direction of the semiconductor substrate has an upper surface-side density peak on the upper surface-side of the semiconductor substrate, and the concentration peak is arranged between the upper surface-side density peak and the upper surface of the semiconductor substrate.