PURPOSE: To improve the heat insulating property of a double-folded roof by connecting an inside folded roof section and an outside folded roof section with fixing tools, and providing insulating materials between reception sections provided at leg frame sections of the fixing tools and the leg frame sections and the folded roof sections.

CONSTITUTION: A double-folded roof 1 is constituted of the first fixing tool 3 fixed to a roof skeleton 2 such as a beam or a main house, the first inside folded roof section 4 held on it, the second fixing tool 5 fixed on the outside face of the first folded roof section 4, and the second outside folded roof section 6 held on it. The first folded roof section 4 and the second folded roof section 6 are made of nearly the same folded roof board 31, and the second fixing tool 5 is provided with a leg frame section 41 fitted on the outer face of the first inside folded roof 4, the second reception section 51 provided above it, and insulating materials 61, 71 inserted between the leg frame section 41 and the second reception section 51 and between the second reception section 51 and the second outside folded roof section 6. The heat conduction between the leg frame section 41 and the second reception section 51 is prevented by the insulating materials 61, 71, and the first folded roof section 4 and the second folded roof section 6 are heat-insulated.