To improve power generation efficiency of the whole solar battery panel by adequately capturing unused scattered light from surrounding cloud, building and atmospheric air.

The solar battery panel is installed on a roof 2 of a south face of a gable house type heptahedral installation stand 1, comprising a plastic material, having a tilt angle corresponding to a latitude. A roof 3 of a north face is made to have the tilt angle larger than that of the south face, and a reflector is bonded on a surface of the roof 3. By arranging a lot of the installation stands 1 on the north, south, east and west, the scattered light from the cloud and the building is made incident to the reflector of the roof 3, and reflected, and then the light is made incident to the solar battery panel of the roof 2 positioned on the north of it, thereby increasing power generation.