PURPOSE: To eliminate the need for setting the roll gap for a finishing pass at every final pass and to improve the accuracy of products in a rolling installation having a roughing mill and a finishing mill in the position near said mill by making the finishing mill shiftable with respect to the finishing line.

CONSTITUTION: A material which is roughly molded with a breakdown mill 1 is reverse-rolled in plural passes with a universal mill 2 and is set at the edges with an edge mill 3, whereby the material is made into an H shape, in rolling of, for example, an H-beam. A universal finishing mill 4 is shifted offline with a quick shifting device X in this stage, and a roll table 4a with a side guide is installed online. The mill 4 is put into the online state by the device X in the stage of finish-rolling in the final pass and the rolling material M is rolled to an H-beam. Since the roll gap of the mill 4 is held constant, the material is finish- rolled with good accuracy.