A wrinkle or misaligned winding caused in a separator roll is inhibited. In a slitting apparatus (6), a conveying direction of a first separator (12a) is changed to a first take-up roller (70U) side by a direction changing roller (68), the first separator is conveyed via a take-up assisting roller (69) which is provided between the direction changing roller and a first touch roller (81U) so as to shorten a roller-to-roller distance to the first touch roller, and the first separator which is being wound is pressed onto a take-up surface by the first touch roller.