According to one embodiment, a semiconductor device includes a first and a second semiconductor layer of a first conductivity type, a third semiconductor layer of a second conductivity type, a source region of the first conductivity type, a first and a second main electrode, trench gates, a first and a second contact region. The third semiconductor layer is provided on the second semiconductor layer provided on the first semiconductor layer. The first main electrode is electrically connected to the first semiconductor layer. The second main electrode is electrically connected to the source region provided on the third semiconductor layer. The trench gates are provided from the third semiconductor layer to the second semiconductor layer. The first and second contact regions electrically connect the second main electrode and the third semiconductor layer. An opening area of the second contact hole is smaller than that of the first contact hole.