In order to investigate atmospheric corrosion of stainless steel, exposure tests were carried out at several locations. By analysis of the test results, it is considered that the distance from the shoreline can be the most significant factor affecting corrosion. Utilizing a developed evaluation method in laboratory and exposure tests, a new alloy of ferritic stainless steel as bright annealed surface was developed, based on the finding that amorphous silicon oxide film is more corrosion resistant against marine atmosphere. The proposed alloy is a type of highly purified 19% chromium ferritic stainless steel covered with a corrosion resistant bright annealed surface film.