PURPOSE: To prolong the life of wiper and also to enable rollchace-free rolling by executing removal of foreign matter which is simply stuck on a rolling roll, removal of foreign mater which is firmly stuck and grinding of roll mark with a single device.

CONSTITUTION: Elastic soft wipers 11 and hard wipers 12 contg. abrasive grain are successively arranged toward the upper stream in the direction of rotation of work rolls 1, 2 and they are attached to wiper holding members in state where the tips of the soft wipers are a little protruded from the tips of the hard wipers. With air cylinders having operating paths with which pressure can be set in at least two steps, the soft wipers are slightly pressurized to the roll surfaces when the soft wipers are used and, when the hard wipers are used, the soft wipers are further pushed in and simultaneously the hard wipers are strongly pressurized to the roll surfaces.