To reduce the setting space and the damage of a furnace wall and to improve the heat efficiency by arranging an indirect heating means and rotating rolls for heating in a heating chamber, forming a preheating zone at the inlet side of the heating chamber and a cooling zone at the outlet side and carrying a metallic strip.

The metallic strip S is passed through a vertical type continuous annealing furnace T, and at the time of coming to the pre-heating zone B at the inlet side of the heating chamber, hot blast is blown to the metallic strip S from each hot blast blowing nozzle 41 and the metallic strip is heated with the convection heating and comes to the heating chamber A. The metallic strip S is contact-heated at about 960°C with the rotating roll 16 for heating. Successively, the molten strip is cooled with a cold blast from the cold blast blowing nozzle 54 in the cooling zone C and ejected to out of the furnace. Then, in the heating chamber A, the protecting atmosphere of a low dew pt. reducing atmosphere or the like, adding hydrogen to nitrogen is supplied. By this constitution, even in the case of being a material having low radiation ratio, the material can efficiently be heated and a series of treatments from the heating to the cooling can be executed in a short time.