To retain a preferred, constant folding width in a feeding state of just enough cloth in right and left directions even when difference in kinds and conditions of cloth exists and folding width is changed, to prevent stitches in pleats from deviating, to prevent pleats from slipping off in right and left directions, to maintain thread tightening so as to have a constant value, to cope with a change in folding width and to save complicated, adjusting, manual operation for feeding cloth by employing a mechanical self-folding equipment while avoiding unstable manual operation when feeding cloth to a sewing equipment in such a folded state that pleats are formed.

When feeding flat, flexible, thin sheet-shaped object to the destination on the extension line perpendicular to the one end of the object and along the surface of it in a state that both right and left sides are fed at the same speed, the object is fed in such a manner that right and left side parts of the object are gradually twisted from the start of feeding to the destination through the middle in such a way that the one end of the object is flat at the start of feeding, gradually becomes narrower and oblique to an object surface in an approached and confronted state at the middle of the extension line and is made to be perpendicular and close to the object surface and to form folds at the destination and both sides of pleat base can mutually be fixed.