Abstract: A method for spreading thin soft rectangular articles such as cloths, unwoven cloths, paper sheets, plastic sheets, etc. (generally called "rectangular sheets") is disclosed. A part of a first side of a rectangular sheet including one corner of a rectangular sheet is suspended in the air as held nearly horizontally by gripping the corner and another point on the side by grippers which are slidable on a horizontal rail. Accordingly, a second side of the rectangular sheet including the one corner is made to hang down nearly vertically. Then the lowermost end of the second side is gripped by another gripper that is movable vertically along a vertical rail. Except for the one corner, the initially held part of the one side is released, and the rectangular sheet is held with the two adjacent corners at the opposite ends of the second side gripped by two grippers which are movable on the rail.