PROBLEM TO BE SOLVED: To provide a film-fixing tool which can surely prevent the detachment of an upper fixing member, has excellent assembling workability, and can increase solar light incident into a green house. SOLUTION: This film-fixing tool for assembling a double structure green house, characterized by comprising a lower fixing member 14 obtained by integrally and outward obliquely forming V-shaped cross section screw pockets 3 at both the ends of an attaching plate 2 to be connected to the frame 1 of the green house, an upper fixing member 15 obtained by vertically disposing a support portion 6 on the center of a reverse concave-shaped cross section film press portion 16 to be superposed on the lower fixing member 14, forming a dent-shaped cross section receiving rail 10 at the tip of the support portion 6, and forming a V-shaped screw pocket 3 in the side wall, and a film press plate 8 to be superposed on the screw pocket 3 of the upper fixing member 15, and by disposing an inner wall film 11 to cover the upper side of the lower fixing member 14, superposing the reverse concave-shaped cross section film press portion 16 on the inner wall film 11, and then obliquely engaging screws 9 with the outward inclined screw pockets 3 of the low fixing member 14 to fix the inner wall film 11.
