A semiconductor device that includes a semiconductor substrate having a first main surface and a second main surface facing each other in a thickness direction, the first main surface including a trench. The trench has a predetermined depth in the thickness direction and has a substantially wedge shape that has a first side surface and a second side surface that face each other and are not parallel to each other, and a first end surface and a second end surface that face each other and are substantially parallel to each other. The first side surface and the second side surface intersect each other at a line, or extension surfaces of the first side surface and the second side surface extended in the thickness direction intersect each other at a line, and the line extends in a first direction that does not align with a cleavage plane of the semiconductor substrate.