To provide a heat insulator laminated structure which efficiently exhausts, to the outer air, the gas like water vapor or an organic volatile matter content sealed inside a waterproofing sheet and the heat insulator laminated structure provided on a surface of a flat roof skeleton, and hardly exfoliates over a long period of time.

A plurality of heat insulating layers being synthetic resin foam plates 1 are arranged on the surface of the flat roof skeleton leaving a space 2 so that they may not come into contact with one another. The water vapor generated from the concrete skeleton, and the gas like the organic volatile matter content generated from an adhesive agent for lamination of the heat insulating layers and the waterproofing sheet 3 are gathered in the space 2. An exhaust pipe 10 with a check valve is boringly arranged and the pressure in the space 2 is lowered so that the waterproof performance by expansion and contraction of the gas, and the durability of the heat insulating laminated structure may be improved.