Abstract: A sliver formed along an inner surface of an outer rotor is drawn out through a hole of an inner rotor which is concentrically provided in and rotated differentially to said outer rotor, whereby drafting of said sliver is effectuated by the relation between the speed of drawing out said sliver and differential speed between the inner and outer rotors. Furthermore, floating movement of the fibers of said sliver is effectively suppressed by use of plural or one centrifugal disk which is pressed onto said sliver while being revolved at the rim of the inner rotor and subjected to self-rotation on its axis.