To provide an enclosure structure for a building, which can maintain a high power generation efficiency without formation of irregularities on the surface of the enclosure such as a roof, nor application of an external force to solar battery modules, and which can form a lightweight enclosure capable of photovoltaic generation.An enclosure structure for a building, comprising an outer film material made of a light transmitting material and arranged on the outer surface side of the building, an inner film material arranged along inside of the outer film material, an intermediate film material disposed between the outer film material and the inner film material, an air supply means for supplying air to the space between the outer film material and the inner film material, and solar battery modules 7 provided on the inner surface of the intermediate film material.