To perform smooth winding and unwinding operation of a shutter by a method wherein the thin section of a composite film formed of a special material is mounted on either the back or the surface of the shutter or on both of the surface and back.

Frame bodies 1a in a U-shape in cross section are erected at intervals of a proper distance, the two ends of a slat 2 are elevated in the frame body 1a in a U-shape in cross section and through manual operation or operation by a power, the slat 2 is elevated in the frame body 1a. In a case of manual operation, key holes 3 are formed in the right and left of the lower part of the slat 2 and by hooking a rod with a hook t the key hole 3, the slat 2 is lowered for closing. In the case of both automatic and manual operation, since the two ends of the slat 2 are elevated along the groove of the frame body 1a, operation is extremely smoothly effected. A composite film 4 formed of a special material is mounted on the back of the slat 2.