To provide a tension edge with which a cushion sheet can be easily spread while being strained over the frame of furniture, etc., in a short time without requiring any special instrument or jig and the edge parts of the cushion sheet spread over the frame can be made into plane.

A face 11 to be abutted to the frame for spreading a cushion sheet 7 is provided, through holes 12 corresponding to plural through holes 13 on the frame are provided concerning a frame fixing part 9, an edge part fixing edge 8 is provided almost perpendicular to the lengthwise edge part of the frame fixing part 9 so as to fix the edge parts of the cushion sheet, and this tension edge is formed from the frame fixing part 9 and the edge part fixing edge 8. Then, by fixing the frame and the frame fixing part 9 while mounting a bolt 14 through the frame and the through hole 12 at the frame fixing part 9, the cushion sheet 2 fixing the edge parts at the edge part fixing edge 8 can be spread while being strained.