PURPOSE: To smoothen the outer peripheral surface of a winding core easily and surely and prevent the generation of creases on the outer peripheral surface by winding a surface member on the outer periphery of an inner surface layer so that the edge parts in the longitudinal direction are superposed and pressing the edge part of the surface member by a pressing member.

CONSTITUTION: An inner surface layer 3 is formed by winding an inner surface tape consisting of an upper quality paper in spiral form on the outer periphery of a body layer 2 consisting of a lamination layer formed by winding a thick paper, and a surface tape 5 coated with an adhesive is wound in spiral form on the reverse surface of the inner surface layer 3, and attached, and the superposed part 6 of the surface tape 5 is pressed towards the axis core by a roller 8 as pressing means. A groove is formed on the inner surface layer, and the edge part of the surface member is fitted into the groove, and the smooth surface layer can be formed.