The invention relates to a method for producing at least one hydrophilic area on a hydrophobic substrate. The method consists in performing an electrochemical reduction of the surface under the following conditions: the reduction is performed in an electrochemical cell which contains an electrolytic solution containing a compound that is a precursor of a reducing agent, said compound having a standard potential of less than −2.7 V relative to the saturated calomel electrode (SCE); the reducing electrode is placed relative to the substrate surface to be treated such that said surface is facing the surface of the electrode, which is the image of the area to be reduced; the reducing electrode is subjected to the formation potential of the reducing agent.