PURPOSE: To rapidly perform shape correction by providing guide members which are engaged with the body of each seperated roll which is movably mounted on a guide shaft and making the interval between the separated rolls adjustable with a moving screw with driving source on which right and left handed screws are cut.

CONSTITUTION: In the upper support rolls 34, the fulcrum of roll bending which is set with a pair of separated support rolls by expanding contracting motion with a hydraulic driving means and straddling means is changed. Roll bending can be rapidly adjusted by pressurizing force with a pressurizing means which is interposed between the bearings of a work roll 22 independently or co-operatively. On the other hand, in the lower support roll 38, the fulcrum of roll bending is changed by setting a pair of the separated support rolls at proper interval by revolving the driving source 17 backwards or forwards, roll bending can be rapidly adjusted and crown control in high-speed rolling is accurately performed. In this way, proper position control with high adaptation can be executed.