A semiconductor device according to one or more embodiments may include: a drain region; a drift region positioned above the drain region; a base region positioned on the drift region; a trench positioned to abut the base region and the drift region; an insulating in the trench; a counter electrode embedded in the insulating film; a gate electrode positioned above the counter electrode and that is embedded in the insulating film; and a source region that abuts the base region and the trench, wherein a thickness of the insulating film between the gate electrode and an interface between the drift region and the base region is larger than a thickness of the insulating film between the gate electrode and an interface between the source region and the base region.