To provide an apparatus for stretching and opening or closing a sheet designed so that a tension can be added to the sheet when moving the sheet to the final position and dislocation or jumping of a moving member can be prevented.

This apparatus for stretching and opening or closing a sheet 1 is obtained by arranging a cam member 21 in an end of a moving member 9 or a crosspiece installed connectedly to the moving member 9 and is designed so that the cam member 21 is abutted on a second supporting member 14 or a frame 13 provided on this side of the second supporting member 14 to urge the moving member 9 in the downward rotational direction and a tension is applied to the sheet 1 when the moving member 9 is moved from the first supporting member 4 to the vicinity of the second supporting member 14 in the apparatus for stretching and opening or closing the sheet 1 comprising the pair of the first and the second supporting members 4 and 14 opposite to each other, a track 8 installed between the two supporting members 4 and 14 and the moving member 9 movably mounted on the track 8 and capable of stretching or opening the sheet 1 between the two supporting members 4 and 14 utilizing the movement the moving member 9 along the track 8.