Abstract: Disclosed are a method and an apparatus for forming a specular protective film in which the intensity of reflected light is made even with a variation in the angle of incidence of the incident light. In the anodic oxidation treatment, the current value applied to a plurality of specular parts is sampled at a predetermined interval (S301), and each sampled value is integrated over time (S302) and the average value is obtained. A comparison is made between an obtained average value and a preset value, and if the average value is greater, the application of current to all the specular parts is stopped (S303). The preset value is the amount of electricity conducted to form an anodic oxide film having a film thickness corresponding to a desired reflectance which is determined from the relation between the preset film thickness of anodic oxide film and the reflectance.