A semiconductor element cooling structure includes a plurality of semiconductor elements, and electrode structure, which has cooling medium channels therein and is electrically connected to the plurality of semiconductor elements. The electrode structure includes an alternating current electrode having the semiconductor elements on each of opposite surfaces, and a plurality of direct current electrodes holding therebetween the alternating current electrode and the semiconductor elements respectively mounted on the opposite surfaces of the alternating current electrode. Each of the alternating current electrode and the direct current electrodes has the cooling medium channels therein.