Abstract: Molten steel in desiliconized, dephosphorized and decarburized in a three-step sequence. In the first-two steps the melt is agitated. In the first step the temperature is also maintained at between 1480.degree.-1380.degree. C. while oxygen is introduced until the silicon content is reduced to 0.20%. In the second step a flux consisting essentially of CaO and 0.2-0.5 parts by weight of CaCl.sub.2 and/or KCl is introduced while maintaining the basicity of the slag at between 3.5-8.0 and the T.Fe value at between 3-10%. The third step involves blowing oxygen onto this melt without using a refining flux.