The semiconductor device of the present invention is a semiconductor device in which a first semiconductor chip including a first field effect transistor for a high-side switch, a second semiconductor chip including a second field effect transistor for a low-side switch, and a third semiconductor chip including a circuit that controls each of the first and second semiconductor chips are sealed with a sealing portion. A lead electrically connected to a pad of the first semiconductor chip for a source of the first field effect transistor and a lead electrically connected to a back-surface electrode of the second semiconductor chip for a drain of the second field effect transistor are disposed on the same side of the sealing portion in a plan view.