The present invention has as its task to be able to impart a high response crown/shape control function to a rolling mill with a response of decrease bending devices inferior to increase bending devices even under conditions causing a decrease roll bending force to act. To achieve this task, before the start of rolling, both the increase bending force and the decrease bending force are made to act and the composite force constituted by a roll bending force which corresponds to the roll balance force is made to act on a work roll chock. At the time of the start of rolling, the decrease bending force is held at a constant value while the increase bending force is made to change and a composite force constituted by a predetermined roll bending force (decrease bending force) is made to act on the work roll chock for rolling. At the time of the end of rolling, the increase bending force is returned to the state before the start of rolling and a composite force with the decrease bending force constituted by the roll bending force corresponding to the roll balance force is made to act on the work roll chock. In that state, the rolling is ended.