A semiconductor device includes a semiconductor part having a recess formed in an upper surface thereof, an insulating member provided in a portion of the recess, a first electrode, a gate insulating film thinner than the insulating member. The first electrode includes a first part provided in another portion of the recess, and a second part provided higher than the insulating member. The gate insulating film is provided between the semiconductor part and the first part. The semiconductor part includes a first layer of a first conductivity type contacting the gate insulating film, second and third layers of a second conductivity type contacting the first layer and being connected to a source contact and a drain contact. The recess is positioned between the source contact and the drain contact when viewed from above. The insulating member is provided between the first part and the third layer.