To automatically attach and detach a form to and from a carrying bed.

A placing part 7 for placing a form 2 on an empty carrying bed 6 is set next to a carry-out part 5 for carrying out the form 2 from a first chain conveyor 4 on an upstream side and a detaching part 11 detaching the used form from the carrying bed 6 is set on a downstream side and a carrying route 3 to which the carry-in part 16 for carrying in the detached used form 2 in a fifth chain conveyor 15 is set is formed next to the detaching part 11 and an attaching apparatus 17 automatically attaching the form 2 of the carry-out part 5 on the empty carrying bed 6 of the placing part 7 and a detaching apparatus 18 for automatically detaching the used form from the carrying bed 6 of the detaching part 11 to carry in the same in the carry-in part 16 are provided on the carrying route 3.