A cooling structure includes a plurality of plate-shaped heat generating members such as battery parts, DC voltage converters and electrical member (e.g., relay). In the cooling structure, the heat generating members are arranged in a plate-thickness direction to have predetermined spaces for forming fluid passages each of which is provided between adjacent heat generating members, and the fluid passages are provided to pass a fluid for cooling the heat generating members. Accordingly, all the heat generating members can be effectively cooled while the cooling structure can be made compact.