A switching element may include a semiconductor substrate, a trench, a gate insulating film, and a gate electrode. A drift region may be in contact with the gate insulating film below the body region. A bottom region may be in contact with the gate insulating film at a bottom surface of the trench. A connection region may be in contact with the gate insulating film at a side surface of the trench and connect the body region and the bottom region. The side surface of the trench may include a first side surface and a second side surface positioned below the first side surface. An inclination angle of the second side surface may be larger than an inclination angle of the first side surface. An interface between the body region and the drift region may be in contact with the gate insulating film at the first side surface.