After forming a passive film coating on Type 304 stainless steel using a new method, we investigated the improvement of corrosion resistance. Coatings were formed using a combination of electrolytic polishing as a pretreatment process, chemical oxidation and cathodic electrolysis as intermediate processes, with curing applied as a final process. The passive film structure formed by the coating was assessed in terms of film thickness and element distribution. Corrosion resistance was assessed in terms of pitting corrosion potential. A model of the film formation is also discussed in this report.