It is an object to reduce concentration of an electric field on an end of a drain electrode of a semiconductor device. A semiconductor device includes an oxide semiconductor film including a first region and a second region; a pair of electrodes which is partly in contact with the oxide semiconductor film; a gate insulating film over the oxide semiconductor film; and a gate electrode that overlaps with part of one of the pair of electrodes and the first region with the gate insulating film provided therebetween. At least part of the first region and part of the second region are between the pair of electrodes. The gate electrode does not overlap with the other of the pair of electrodes.