PURPOSE: To shorten the length of a compensating furnace and to improve a rolling speed by feeding continuously cast untreated materials to a multistage reversible finishing rolling path and a coil box succeeding to it after hardening.

CONSTITUTION: When a continuous casting device is operated, strands 5, 6 are manufactured. When the strands reach a desired length respectively, the strands are cut by cutting machines 7 or 8 and heated by the compensating furnaces 3 or 4. Further, the strand 5 is sent to a reversible finishing mill 10 via a roller conveyer 9. On the other hand, the strand 6 coming from the compensating furnace 4 is carried in the direction shown by an arrow 27 by the use of a capsuled horizontally delivering device 26 and a horizontally displacing device and reaches the feeding roller conveyer 9. The strand 6 is not capsuled and moreover directly fed to the finishing rolling path 10 without using an intermediate storage device or a holding furnace. The strands 5, 6 are alternately and continuously fed to the finishing rolling path 10 from the compensating furnaces 3, 4. Steel is removed by devices 11, 12 succeeding to rolling mills F1 and F2, and the strand is easily coiled by a coil box 14 without any trouble.