PURPOSE: To provide a roll bending function to work rolls and to enable correction and control of the compound elongation of a rolled material by forming the intermediate rolls between the work rolls and backup rolls of a rolling mill into a sleeve type construction and making said rolls movable relatively in the axial direction.

CONSTITUTION: A rolling material 11 is rolled with a rolling mill having upper and lower work rolls 12, 13, intermediate rolls 16, 17 and backup rolls 14, 15. The rolls 16, 17 are formed with liquid pressure chambers 18 between outside circumferential sleeves 16A, 17A and shafts 16B, 17B and are made movable relatively to the opposite sides in the axial direction. The rolls 16, 17 form a projecting crown by the pressure oil supplied into the chambers 18 and at the same time the rolls 16, 17 move in the directions opposite from each other in the axial direction, by which the roll bending function is given to the rolls 12, 13, and therefore the correction and control of the simple elongation and end elongation of the material 11 are made possible and the material 11 having the excellent accuracy of the plate thickness in the plate width direction and the good shape of the plate is manufactured.