To prevent the defect in a conventional method by providing a new economical and effective method solving the problem of the wrinkle formed in a vertical treating furnace for a steel strip.

In the method for reducing wrinkle formed in the heating range in a continuous heat treatment line for metal strip (3), such as an annealing, a galvanizing line, with radiant tubes (4), in the method for passing the strip (3) through on carrying and/or returning rollers (2) in the furnace to correct the temperature state of the rollers (2), the above correction is directly performed by changing the heating with the radiant tubes (4) positioned near the rollers (2). In this way, the heat flow with the radiant tubes (4) is directly controlled against the rollers (2).