According to one embodiment, a semiconductor device includes first and second electrodes, first, second, and third semiconductor regions, an insulating part, a conductive part, and a gate electrode. The first semiconductor region is provided on the first electrode and is electrically connected to the first electrode. The second semiconductor region is provided on the first semiconductor region. The third semiconductor region is provided on the second semiconductor region. The insulating part is provided on the first electrode. The conductive part is provided in the insulating part and is arranged with the first semiconductor region. The gate electrode is provided in the insulating part. The gate electrode is positioned above the conductive part and is arranged with the second semiconductor region. The second electrode is provided on the third semiconductor region and the insulating part, and is electrically connected to the third semiconductor region.