Most metals are used in environments in which they are thermodynamically unstable, reaction products thus forming on the metal surfaces; these reaction products may be protective, preventing further reaction of the metal with the environment. The ideal technique for studying these corrosion films is non-destructive, capable of in situ analysis, and capable of analyzing both the elementary chemistry and the molecular or crystal structure of the corrosion product film. Raman microprobe offers distinct advantages over other currently available analytical technques. -- AATA