A semiconductor includes a first electrode, a first semiconductor region, a second semiconductor region, a third semiconductor region, and a gate electrode. The gate electrode has a first portion arranged with the second semiconductor region in a direction perpendicular to a first direction extending from the first electrode to the first semiconductor region, and has a second portion on the first portion. The semiconductor also includes a gate insulating layer between the gate electrode and each of the three semiconductor regions. The gate insulating layer extends to the upper surface of the third semiconductor region to form an extending portion. The second portion of the gate electrode protrudes in an upward direction from the upper surface of the extending portion of the gate insulating layer, and a lower part of the second portion of the gate electrode is embedded in the first portion of the gate electrode.