PURPOSE: To perform rapidly the shape control of a rolling material by disposing a roll supporting chock housing slidably in the roll-axis direction and fitting a bending chock housing to the end part of roll axis and providing a bending cylinder to the space between the chock housings mentioned above.

CONSTITUTION: Arms 2a are fixed in one body to each roll chock housing 2 used for supporting a work roll 1 to form its plane shape into an approximately channel shape, and each roll chock housing 2 is fitted slidably in the roll-axis direction to bending beams 4, 4 disposed between housings 3 through the outside grooves 2b of the arms 2a. A bending chock 6 provided with vertical bending cylinders 5 is fitted to each axial-end part of roll 1, to bring the pistons of cylinders 5 into contact with the upper and lower surfaces of the inside groove 2c of each arm 2a. By these mechanisms, the change of the stroke of bending cylinder 5 is not required even when the roll diameter is changed, and the housing is not influenced by the roll bending.