PURPOSE: To enable shape correction of a metallic strip by various methods by disposing a tension leveler between an un-coiler and coiler and changing over a passage route for the strip.

CONSTITUTION: A strip W is charged from the un-coiler 4 via a guide roller 16e, a degreasing device 9, etc., into an annealing furnace 2 and is annealed to straighten the annealed strip W ejected from the annealing furnace 2. The strip is thereafter passed through the tension leveler 12 via a cooler 3..., guide rollers 16f, 16a, 16b, 16c and is coiled by the coiler 5 from a guide roller 16d. On the other hand, the strip W from the un-coiler 4 is passed through the above- mentioned lever 12 via the roller 16c and is passed through the annealing furnace 2, the cooler 3... the roller 16f via the rollers 16d, 16a, 16b, 16e, etc., and is coiled by the coiler 5 in order to correct the shape of the strip W prior to the annealing. The above-mentioned two operations are thereby executed with one unit of the above-mentioned leveler 12.