A semiconductor device according to an embodiment includes an N-well region, a first gate electrode, a columnar epitaxial layer, and a first contact. The N-well region includes two P-type impurity diffusion regions. The first gate electrode is provided above the N-well region between the two P-type impurity diffusion regions. The first gate electrode are opposed to the N-well region via a gate insulating film. The columnar epitaxial layer is provided on the P-type impurity diffusion region. The epitaxial layer includes a first semiconductor layer including P-type impurities. The first contact is provided on the first semiconductor layer of the epitaxial layer.