In order to improve the understanding of the hydrogen metal interaction, we have studied the influence of the surface state of a thin film f palladium on the hydrogen permeation process. Energetic desorption values Ed have been calculated by thermal programmed desorption experiments for various pretreatments of the sample. Auger spectral analysis shows that carbon, sulphur and oxygen are present at the surface of the metal. Results allow us to conclude that the increase in Ed is certainly connected with an increase in concentration of sulphur at the surface.