A semiconductor device may include a fin structure having source/drain regions and channel fins connected between source/drain patterns. A gate insulation layer may be provided on the channel fins. A gate electrode may include lower gate patterns and an upper gate pattern. The lower gate patterns may extend in a vertical direction and contact the gate insulation layer. The upper gate pattern may extend in a second horizontal direction substantially perpendicular to the first horizontal direction. The upper gate pattern may be connected to upper portions of the lower gate patterns.