The present invention improves the performance of a semiconductor device. As a means therefor, the present invention forms a semiconductor device comprising: a semiconductor substrate having a drift layer of a first conductivity type, a body region of a second conductivity type, and a JFET region of the first conductivity type being in contact with the body region on both sides on the drift layer; a plurality of trenches formed in an upper surface of the semiconductor substrate and extending in a first direction; and a gate electrode formed in the trenches and on the upper surface of the semiconductor substrate with an insulating film interposed therebetween. In a unit cell, a first trench group composed of a plurality of trenches lined up in a second direction that is orthogonal to the first direction and a second trench group composed of a plurality of trenches lined up in the second direction are lined up in the first direction, and have a channel region that is shallower than the trenches in a lower surface of a source region between adjacent trenches in the second direction. The gate electrode comprises a plurality of first portions in the trenches, and a second portion that is positioned on the semiconductor substrate and connects the first portions lined up in the first direction and the second direction to one another, and has a plurality of JFET regions per unit cell.