A semiconductor device according to an embodiment comprises a semiconductor element, a first terminal, a plurality of second terminals, and an encloser. The semiconductor element is rectangular. The first terminal has an upper surface to which a back surface of the semiconductor element is bonded. The second terminals are arranged around the first terminal. The second terminals are arranged at four corners of the encloser to be exposed from the bottom surface, and sides of the semiconductor element are opposed to the first side, the second side, the third side, and the fourth side, respectively. The first terminal is apart from the first side surface and the third side surface, a lower surface of the first terminal is exposed from the bottom surface, and the first terminal is partly exposed from the second side surface and the fourth side surface.