In a vertical MOSFET in which bottom portions of each gate electrode formed in a ditch are extended toward the drain region, the on resistance is reduced while preventing voltage resistance reduction and switching speed reduction caused by a capacitance increase between the gate and drain. A vertical MOSFET includes first ditches, second ditches, and gate electrodes. The first ditches are formed in an upper surface portion of an epitaxial layer formed over a semiconductor substrate and extend in a second direction extending along a main surface of the semiconductor substrate. The second ditches are formed in bottom surface portions of each of the first ditches and are arranged in the second direction. The gate electrodes are formed in the first ditches and second ditches. The gate electrodes formed in the first ditches include lower electrodes arranged in the second direction.