A bench scale experiment was conducted to clarify relations between the salt film (S.F.) treatment conditions and the descaling of stainless steels. The results are summarized as follows: (1) An aqueous solution of Na₂CO₃-NaNO₃-NaOH system was suitable for the cooling type S.F. treatment, because the solution was applicable to a variety of steels and at a wide temperature range. (2) For the temperature raising type, it was necesssry to use a heating furnace with an atmosphere containing little carbon dioxide to protect alkali hydroxide from carbonation, and the descaling was liable to be nonuniform. (3) Spraying of the S.F. solution through air jet type nozzles gave relatively good results, but there were still many problems to be solved.