In a semiconductor device, a first conductivity-type first semiconductor region that abuts on a side surface of a contact trench adjacent to an opening portion of the contact trench, and has a higher impurity concentration than that of a second semiconductor layer is formed. Also, a second conductivity-type second semiconductor region that abuts on a bottom surface of the contact trench and a side surface of the contact trench adjacent to the bottom surface of the contact trench, and has a higher impurity concentration than that of a first semiconductor layer is formed. A first electrode that is connected electrically with the first semiconductor region and the second semiconductor region is disposed in the contact trench. Even when the semiconductor device is miniaturized by reducing the width of the contact trench, a breakage of the semiconductor device when switched from an on-state to an off-state is reduced.