A semiconductor device includes a vertical trench gate element portion and a lateral n-channel element portion for control which includes a well diffusion region, and a junction edge termination region which surrounds the vertical trench gate element portion and the lateral n-channel element portion for control. The junction edge termination region includes an oxide layer, a sustain region in contact with a trench provided at the end, and a diffusion region in contact with the sustain region. The diffusion region is deeper than the base region and has low concentration. The sustain region is shallower than the diffusion region and has high concentration. The well diffusion region is deeper than the base region and the sustain region and has low concentration. The breakdown voltage of the junction edge termination region and the well diffusion region is higher than that of the vertical trench gate element portion.