To carry a sheet material by an unretreating means among plural provided carrying means, and prevent the occurrence of a curl and wrinkles by a carry by retreating the carrying means from a paper refeeding carrying passage according to a carrying directional length of the sheet material to be reversed.

When a sheet material smaller than A4 size is reversed and discharged, first and second curl removing roller pairs 72 and 80 are put in a condition of not retreating from a paper refeeding carrying passage R2, and it is reversed and discharged. That is, it is carried up to a position 55 where the rear end of the sheet material passes through a first flapper 53 and a second flapper 54 by passing through a nip of the first curl removing roller pairs 72 from a first paper path 74 of a curl removing unit 70. The carrying direction of the first and the second curl removing roller pairs 72 and 80 is reversed, and it is carried in the arrow Al direction, and is returned to a carrying passage R1, and is discharged to a discharge part 20 by reversing the obverse and the reverse of the sheet material. Then, since a sandwiching distance between the first and the second curl removing roller pairs 72 and 80 is short, wrinkles are not caused.