PURPOSE: To hold a plate material between rolls easily by adapting a rotational body with an inner surface concentric with a sub-roll and an outer surface eccentric with the sub-roll to be rotatable by the operation of a handle.

CONSTITUTION: A roll movement device 5 is provided with a fixed bracket 6 surrounding a sub-roll 4 with a partially-cylindrical inner surface 6', a partially- cylindrical body of rotation 7 set between the sub-roll 4 and the fixed bracket 6, and a plurality of small-diameter rolls 8 respectively suspended within the radius of the body of rotation 7 to catch the outer surface of the sub-roll 4 to be rollable, while a rotational operation handle 10 is projected on the right side of the body of rotation 7 with a fixed plate 9 between. Meanwhile, an outer surface 7' of the body of rotation 7 and the inner surface 6' of the fixed bracket 6 are eccentric with the sub-roll 4. When the handle 10 is turned, the sub-roll 4 is moved to separate from a main roll 3.