PURPOSE: To always make the force required for moving a roll constant by enabling the synchronism between the vertical movement of rolling-down screw and the vertical movement of bearing cases of an upper roll by controlling a balanced valve in the hydraulic control circuit.

CONSTITUTION: The rolling-down screw 1 which is provided through the housing 5 of rolling mill and with which the vertical moving amount of the upper roll is set and safety mortar 8 which is set on the top surface of the bearing case 4 of the upper roll and adhering closely to the tip of the aforementioned rolling- down screw are provided. A pair of shafts 2 for supporting upper roll which are provided on both sides so that the aforementioned rolling-down screw is held between them and of which one end is connected with the aforementioned bearing cases 4 of the upper roll with pins. The other end of the aforementioned shafts 2 for supporting upper roll is connected to an actuator which is fixed on the aforementioned housing of the rolling mill with pins. In this way, the force required for moving the roll is fixed, comparatively large rolling reduction can be dealt with and the change of roll interval is rapidly executed.