According to an embodiment, a trench structure and a second semiconductor layer are provided in a semiconductor device. In the trench structure, a trench is provided in a surface of a device termination portion with a first semiconductor layer of a first conductive type including a device portion and the device termination portion, and an insulator is buried in the trench in such a manner to cover the trench. The second semiconductor layer, which is of a second conductive type, is provided on the surface of the first semiconductor layer, is in contact with at least a side on the device portion of the trench, and has a smaller depth than the trench. The insulator and a top passivation film for the semiconductor device are made of the same material.