Device and method for shifting work roll of cluster mill

The present inventive device for shifting a work roll of a cluster mill employs a roll shifting cylinder (14) to rotate a lever arm (12) by driving a roll shifting cylinder (14) so as to shift a work roll (1) through a thrust bearing (15), performing an automatic positioning control by a control part (27) so that a target roll shift position can be attained based on the track record value of shift amount of the thrust bearing (15) detected by a shift amount detection sensor (16), and holding a specified clearance amount between the end face of the work roll (1) and the thrust bearing (15) during rolling operation so as to use a chockless mill as a work roll shift mill.