To disperse external force applied to a surface body to make tensile stress small to prevent the damage of the surface body by fixing the flexible surface body by a line, and to ensure the fixing the surface body and also to fix upper and lower two surface nature bodies at a time, and to easily perform renewal work of the surface body in a short period of time.

A fixing device of a flexible surface body consists of a fixing plate 1 which is fixed to backing such as ground and concrete and on which a fitting member is erected, a long-length member b1 on which the end part of the flexible surface body is rolled up, and a pressing plate 3 fitted to the fitting member 1 and for pressing the upper part of the flexible surface body rolled up on the long-length member 21. The flexible surface body is made a water barrier sheet or light shielding sheet laid on a reclamation final disposal site for waste or the like.