To provide adiabatic waterproof structure by a mechanical fixing method and a construction method, capable of fixing surely a heat insulating material and a water-proof sheet, even in high adiabatic specification, and capable of saving labors, and free from a noise problem.

In this adiabatic water-proof structure, a lower screw part of a composite screw having the lower screw part and an upper long nut part fixed to a water-proof backing A is screwed in a prescribed position of the water-proof backing A under the condition where the upper long nut part fixed is projected, a hole is opened in the heat insulating material B to make the upper long nut part viewed from an upper side, under the condition where the upper long nut part does not exceed an upper face of the laid heat insulating material B, the heat insulating material B is laid on the water-proof backing A, a water-proof fixing metal 2 is mounted on the water-proof backing A in the upper long nut part position, a fixing screw 3 is screwed in the upper long nut part from an upper side of the water-proof fixing metal 2, the heat insulating material B is fixed onto the water-proof backing A, a water-proof sheet C is laid on the heat insulating material B, and the water-proof sheet C is fused to the water-proof fixing metal 2 by an induction heating method.