In order to determine the best chemical surface state of a polyimide (PI) sample to obtain good metal polymer adhesion, the chemical changes occurring on the PI surface following different treatments were studied by X-ray photoelectron spectroscopy. The effect of alcohol ultrasonic cleaning, optionally followed by PI heating, as well as the effects of exposure to an Ar and to an 0 plasma were therefore analyzed. It was concluded that an efficient way to treat the PI sample prior to non-reactive metal deposition is simply to clean it in an alcohol ultrasonic bath, then to heat it to approximately 150-degrees-C. Its surface composition becomes very similar to its bulk composition. The adsorbed nitrogen which prevents nucleation of metallic atoms on and below the PI sample is thereby totally desorbed.