To obtain clean energy by forming a roof board with solar cells by integrally attaching a solar cell module to sections for roof board formed of aluminum extruded sections or thin plate for roof board.

This comprises a long-sized section 10 for roof board with a wide flat portion 11 formed by aluminum extrusion and a flexible solar cell module 40 formed into the same external shape as a flat portion of section 10 for roof board, and a solar cell module 40 is adhered to the flat portion 11 of the section for roof board 10 thereby forming them together in one united body. Then, a strengthened transparent cover having the same shape as the solar cell module 40 is attached for integral construction.