To efficiently supply fuel to a fuel cell and a cooling medium to a superconducting battery, and to effectively utilize the cooling by the cooling medium of the 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 this power source device of a motor for a vehicle using the superconducting battery charged by the power from a fuel cell as a power source, a means for supplying hydrogen produced by supplying the power from a solar battery to a water decomposing device for the electrolysis of water, to the fuel cell, is mounted, the superconducting battery to which the 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 a cabin, and the cabin can be cooled by opening the opening and closing part of the heat insulated case.