PURPOSE: To prevent the generation of roll mark by shifting a support roll in a set position at high speed and oscillating the support roll at slow speed.

CONSTITUTION: A position detector, hydraulic solenoid valve 83 for high-speed movement and hydraulic solenoid valve 84 for slow-speed movement for moving the support roll 34L with a hydraulic cylinder 56L are mounted. The solenoid valves 83, 84 are controlled with a controller 82 based on signals from a host and the signals of the position detector. In the initial stage, the support roll is moved to a preset position at high speed by driving the hydraulic cylinder 56L for adjusting position and energizing the hydraulic solenoid valve 83 for high-speed movement. To prevent the generation of roll mark that is generated on the surface of a material to be rolled, the support roll is oscillated by using the hydraulic solenoid valve 84 for slow-speed movement and specifying the speed of the support roll 34.