To obtain a cushion material capable of preventing a seating position from slipping, a cover from slipping down, etc., by using a specific pleated fabric having remarkably different surface frictional resistance values in different directions as the side fabric on the seating position of the cushioning material.

Polyester multifilament yarns or their processed yarns are used to produce a plain ground tissue. During the production an operation for winding up the tissue is once stopped, and a tissue comprising only warps and wefts for a pleat portion is formed. The tension of a beam is loosened, and the formed tissue is beaten up. The pleated fabric thus produced has pleats having a length of ≤2 mm and having a larger distance than the length of the pleats between the adjacent pleats on the surface of the fabric, and further has a difference of ≥300 g between the frictional forces on the surface of the fabric in the direction crossing to the pleats and in the direction different from the crossing direction by an angle of 180°. The pleated material is used as a side fabric on the seating side of a cushion material comprising the side fabric and a filler surrounded with the side fabric, and the side fabric on the opposite side is immersed in a (foamed) urethane resin, a silicone resin, etc., to apply an antislipping processing treatment.