A roll stamping apparatus comprising: sets of rollers (10, 20, 40, 50) rotating while facing each other so as to press opposite surfaces of a material which is continuously supplied to move between the rollers (10, 20, 40, 50); and molding portions (11a, 11b, 41a, 41b, 51a, 51b) having a stamping structure applied to outer surfaces of the sets of rollers (10, 20, 40, 50) so as to mold the material, wherein a plurality of sets of rollers (10, 20, 40, 50) are disposed in a movement direction of the material, the respective molding portions (11a, 11b, 41a, 41b, 51a, 51b) of the sets of rollers (10, 20, 40, 50) are formed to sequentially change a cross section of the material in the movement direction of the material, characterised in that at least one of the sets of rollers before a final set of rollers through which the material finally passes is a set of over-molding rollers having molding portions (51a, 51b) of which a length in a circumferential direction is longer than a length of the molding portions (41a, 41b) of the final set of rollers, the molding portions (41a, 41b, 51, 51b) of the final set of rollers and the set of over-molding rollers comprise flat portions (41a, 41b, 51, 51b) having the same cross section and a predetermined length in a circumferential direction, and transition portions positioned on both sides of the flat portion (41a, 41b, 51, 51b) and in which a cross section is changed in the circumferential direction, wherein a length (L3a) of the flat portion (51a, 51b) of the set of over-molding rollers in the circumferential direction is either: a) equal to a length (L2a) of the flat portion (41a, 41b) of the final set of rollers in the circumferential direction, and a length (L3b) of the transition portion of the set of over-molding rollers in the circumferential direction is longer than a length <L2b) of the transition portion of the final set of rollers in the circumferential direction, to cause reverse deformation only at the transition portion of the final set of rollers; or b) longer than a length (L2a) of the flat portion (41a, 41b) of the final set of rollers in the circumferential direction to cause reverse deformation only at the transition portion of the final set of rollers. sets of rollers (10, 20, 40, 50) rotating while facing each other so as to press opposite surfaces of a material which is continuously supplied to move between the rollers (10, 20, 40, 50); and molding portions (11a, 11b, 41a, 41b, 51a, 51b) having a stamping structure applied to outer surfaces of the sets of rollers (10, 20, 40, 50) so as to mold the material, wherein a plurality of sets of rollers (10, 20, 40, 50) are disposed in a movement direction of the material, the respective molding portions (11a, 11b, 41a, 41b, 51a, 51b) of the sets of rollers (10, 20, 40, 50) are formed to sequentially change a cross section of the material in the movement direction of the material, characterised in that at least one of the sets of rollers before a final set of rollers through which the material finally passes is a set of over-molding rollers having molding portions (51a, 51b) of which a length in a circumferential direction is longer than a length of the molding portions (41a, 41b) of the final set of rollers, the molding portions (41a, 41b, 51, 51b) of the final set of rollers and the set of over-molding rollers comprise flat portions (41a, 41b, 51, 51b) having the same cross section and a predetermined length in a circumferential direction, and transition portions positioned on both sides of the flat portion (41a, 41b, 51, 51b) and in which a cross section is changed in the circumferential direction, wherein a length (L3a) of the flat portion (51a, 51b) of the set of over-molding rollers in the circumferential direction is either: a) equal to a length (L2a) of the flat portion (41a, 41b) of the final set of rollers in the circumferential direction, and a length (L3b) of the transition portion of the set of over-molding rollers in the circumferential direction is longer than a length <L2b) of the transition portion of the final set of rollers in the circumferential direction, to cause reverse deformation only at the transition portion of the final set of rollers; or b) longer than a length (L2a) of the flat portion (41a, 41b) of the final set of rollers in the circumferential direction to cause reverse deformation only at the transition portion of the final set of rollers. a) equal to a length (L2a) of the flat portion (41a, 41b) of the final set of rollers in the circumferential direction, and a length (L3b) of the transition portion of the set of over-molding rollers in the circumferential direction is longer than a length <L2b) of the transition portion of the final set of rollers in the circumferential direction, to cause reverse deformation only at the transition portion of the final set of rollers; or b) longer than a length (L2a) of the flat portion (41a, 41b) of the final set of rollers in the circumferential direction to cause reverse deformation only at the transition portion of the final set of rollers.