sufficiently stretched state accordingly unevenness is remarkably reduced especially massive migration of lapped fibers at the time of ending of slivers is effectively controlled by this porcupine roller and a sliver having a very good evenness can be manufactured as will be apparent from the foregoing description according to the present invention between a front roller and a back roller at the gilling or bobinoir step of the worsted spinning process a porcupine roller is arranged on the side of the front roller and an intermediate roller comprising double aprons or a balloon roller and an apron is arranged on the side of the back roller to construct a series of a draft apparatus and the apron is driven and rotated by the forefront roller of rollers supporting said apron by virtue of such characteristic features the spron of the intermediate roller is rotated in the state where the sliver holding surface is kept under tension and therefore the sliver supplied from the back roller is smoothly held and delivered out under tension without being bent accordingly a high draft can always be given to the sliver precisely and by the combing action of the porcupine roller fibers of the sliver are sufficiently controlled and uneveness due to the joining operation is not caused to occur at all therefore a sliver having a good uniformity and being free of unevenness can always be spun out furthermore in the present invention the porcupine roller and the intermediate roller comprising a lower apron and an upper balloon roller or double roller 3 which is positively driven and rotated by the forefront roller can easily.