roll every time two materials were rolled it was confirmed that the measured values were included within the variation range shown in fig9 also the high spots as shown in fig4 will not occur fifty materials shown in table 2 the width was changed were rolled in succession under the conditions shown in table 2 by using the finish rolling mill shown in table 1 as in example 1 and setting work rolls shown in fig7 tan u03b8 1 0 u00d7 10 3 at the sixth stand as the work rolls and work rolls having a substantially flat crown at all of other stands the results are shown in fig1 in this example the effective shift quantity was set between 80 mm and 120 mm and the wear quantity m per material was 3 u03bcm u02dc 6 u03bcm the correction of the movement of the taper initiating point by the wear of the roll was performed for every two materials within the range of the 25th material to the 33rd material and the correction was performed for every material in other materials in fig1 c25 and c75 indicate the crown quantities at a point 25 mm away from the side edge and a point 75 mm away from the side edge respectively it is seen that the effect of the present invention was stably attained even in the 50th rolled material and a high effect was attained even at the point where the thickness of the material to be rolled was changed and the high spot did not occur from the results of the foregoing.