A semiconductor device includes: a high-side transistor having a first gate electrode, first drain electrodes and first source electrodes; a low-side transistor having a second gate electrode, second drain electrodes and second source electrodes; a plurality of first drain pads that are disposed above the first drain electrodes and are electrically connected to the first drain electrodes; a plurality of first source pads that are disposed above the second source electrodes and are electrically connected to the second source electrodes; a plurality of first common interconnects that are disposed above the first source electrodes and above the second drain electrodes and are electrically connected to the first source electrodes and the second drain electrodes; and a plurality of second common interconnects that are connected to the first common interconnects, and extend in a direction that intersects with the first common interconnects.