To provide a manufacturing method which can secure a polishing cloth for finish polishing having a soft plastic foam in uniform thickness.

In a coating step, a polyurethane resin solution 45 is applied to a substrate 43 by a knife coater 46. In a conveyance step, the substrate 43 coated with the polyurethane resin solution 45 is conveyed for a prescribed time to a coagulating tank 20 while being almost horizontally supported by support rollers 48. The duration of conveying the substrate 43 almost horizontally is preset as 60 to 300 sec. In an immersing step, the substrate 43 coated with the polyurethane resin solution 45 and conveyed is almost vertically introduced into a coagulating liquid 25 from a guide roller 21 toward a guide roller 22. The polyurethane resin is coagulated and regenerated in the coagulating liquid 25. While the substrate 43 is being conveyed almost horizontally, the polyurethane resin solution 45 flows so as to allow a portion which is large in thickness to become smaller.