In order to decrease the silica content in 16% Cr ferritic stainless steel, the phases present in deoxidized inclusions were predicted by the FACT model. To decrease the amount of deoxidized inclusions and slag inclusions in the melt, the capacity of alumina absorption was compared using different top slags. In trial tests, the cleanliness of slabs was significantly improved in 16% Cr ferritic stainless steel produced by AOD processes and the number of surface defects of cold coils was also significantly reduced.