PURPOSE: To improve the operability of roll exchange in a rolling device by respectively providing a pair of through-guides on width adjusting devices and supporting a truck by placing an inner stand on a truck and providing an elevating device.

CONSTITUTION: First, the elevating device 8 is lowered to the lowermost limit and the truck 9 is placed on rails 14. Next, by putting an upper roll 301 on the parting plates 12 of the inner stand 2 and a lower roll 3-2 on the truck 9, and pulling the truck 9, the upper roll 3-1 and inner stand 2 are drawn out of a housing 1 and carried out to an off-line place. In off-line roll exchange, by hanging out the upper roll 3-1 with a crane, hanging the inner stand 2 with the crane and pulling the truck 9, the lower roll 3-2 is taken out. In such a way, roll exchange is executed while placing the elevating device 8 on the housing 1 as it is and placing the through-guide 15 and width adjusting mechanisms 6, 7 on the inner stand 2 as it is.