To promptly and easily convert and recover a large brake press working device to a roll processing device, thus, to shorten a processing preparation time, and to improve productivity of roll processed products and reduce manufacturing cost.

This roll processing unit 1 includes: a reception side roller attachment 11 detachably mounted to a lower mold 6 side of the brake press working device 2; a pressing side roller attachment 12 detachably mounted to an upper mold 7 side of the brake press working device 2; and a swing arm mechanism 13 carrying both of the attachments 11, 12 between storage positions 11a, 12a separated from the brake press working device 2 and use positions 11b, 12b located on the side of the brake press working device 2. Together with the swing arm mechanism 13, both of the attachment 11, 12 placed in the storage positions 11a, 12a are stored in an underground storage pit 37 formed adjacent to the brake press working device 2.