A semiconductor device is provided, including: a semiconductor substrate having an active area and an edge termination region; an upper electrode; an insulating film provided between the semiconductor substrate and the upper electrode and having a contact hole; a first conductivity-type drift region; a second conductivity-type base region; a second conductivity-type well region; and a second conductivity-type extension region formed extending in a direction toward the well region from the base region and separated from the upper electrode by the insulating film, wherein a sum of a first distance from an end portion of the contact hole closer to the well region to an end portion of the extension region closer to the well region and a second distance from the end portion of the extension region closer to the well region to the well region is smaller than a thickness of the semiconductor substrate in the active area.