It is an object to provide the techniques capable of restraining avalanche breakdown at cells opposite to a corner portion of a gate pad. A MOSFET is provided with a corner cell, which is disposed in a region opposite to a corner portion of a gate pad in a planar view, and an internal cell, which is disposed in a region in the opposite side of the gate pad with respect to the corner cell. In a contour shape of the corner cell, a longest distance among distances each of which is shortest distance between a longest side and each of sides opposite to the longest side is equal to or less than two times of a length of one of equal sides or a short side of the internal cell.