A semiconductor device includes an element layer, plural source electrodes, plural drain electrodes, plural gate electrodes, a source bus bar, a drain bus bar, a first gate bus bar, and a second gate bus bar. The source electrodes, the drain electrodes, and the gate electrodes are disposed on the element layer and extend along a first direction. The gate electrodes are respectively disposed between the source and drain electrodes. The source and drain bus bars and the first and second gate bus bars extend along a second direction interlaced with the first direction. The source bus bar and the drain bus bar are electrically connected to the source electrodes and the drain electrodes, respectively. The first and second gate bus bars are connected to the gate electrodes. The first bus bar is disposed at one end of the source electrodes. The source electrode crosses the second gate bus bar.