By turning toward the radially outer direction a turned-up region of a tire component by reciprocating turning fingers, and by positioning the reciprocation centre (the base of a short finger part) of the turning finger at the immediate vicinity of the departing point of the tire component from a bead-locking device, the compressing force provided at the turned-up region in the vicinity of the bead is effectively decreased, and therefore the generation of creasing is controlled.