According to one embodiment, a semiconductor device includes: a substrate; a first circuit portion; and a second circuit portion. The first circuit portion includes: a first and a second switching elements, and a first and a second diodes. The second circuit portion includes a third and a fourth switching elements, and a third and a fourth diodes. The first switching element is juxtaposed with the second switching element in a first direction, and is juxtaposed with the fourth switching element in a second direction. The third switching element is juxtaposed with the fourth switching element in the first direction, and is juxtaposed with the second switching element in the second direction. A voltage is applied to electrodes of the first and third switching elements. A voltage of a polarity opposite the first voltage is applied to electrodes of the second and fourth switching elements.