To effectively utilize the cooling by a cooling medium of a superconducting battery for cooling a cabin by mounting the comparatively large superconducting battery at a lower part of the cabin causing no hindrance there in a power source deice of a motor for a vehicle utilizing the superconducting battery cooled by the cooling medium as a power source.

A superconducting battery to which a cooling medium is supplied is accommodated in a heat insulated case provided with an opening and closing part, the heat insulated case is mounted at a lower part of the cabin, and the cabin is cooled by opening the opening and closing part of the heat insulated case.