PURPOSE: To correct easily cambers and to improve productivity by rolling a material with the right and left vertical rolls of an edger at different peripheral speeds in accordance with the camber quantity of the material.

CONSTITUTION: The peripheral speeds of rolls 1, 2 are made different or equal according to the distribution condition of the camber of a material 4 in its longitudinal direction. More specifically, if only the preceding end of the material is bent transversely, the peripheral speeds are varied at that part alone and the material is rolled at an equal speed except for said part. If the entire part of the material 4 is bent transversely at the same curvature, the material is rolled at the fixed different peripheral rolls. In case of the curvature differs, the difference between the peripheral speeds is changed in accordance with the curvatures. The material 4 in this stage is edged in an arrow (a) direction with the vertical rolls 1, 2, whereafter the material is horizontally rolled with horizontal rolls 11, 12, then the mill is ideally suited as a hot strip mill. If the material is edged with the rolls 1, 2 after horizontal rolling with the rolls 11, 12, the mill is ideally suited as a thick plate mill with reverse rolling. The edger is further convenient for a thick plate mill with reverse rolling if the rolls 11, 12 are disposed between two sets of the vertical rolls 1, 2 and 13, 14.