PURPOSE: To eliminate the need for installing a free looper by making a band steel form a tensile force system between a leveler and a pinch roll and specifying the distance between the end part of a side guide on the leveler side and the middle point of a leveler in the longitudinal direction of the band steel.

CONSTITUTION: A distance L between the middle point 4A of a leveler 4 in the longitudinal direction of a band steel and the end part 9A of a side guide 9 on the leveler side is set so as to satisfy a certain equation relating to the ratio of the plate width W to the plate thickness (t) of the band steel. And, by strongly restricting the band steel through the leveler 4 to absorb tensile force in the opposite direction of a pay-off reel not shown in figure on the front side of the leveler 4 while, on its rear side, to provide tensile force in the opposite direction for maintaining a line up to a pinch roll 12, a tensile force system is formed between the leveler 4 and the pinch roll 12. Due to this construction, the installation of a free looper between the levelver 4 and the pinch roll 12 can be eliminated.