The development of a pickling process, more effective and appropriatefor the new steel grades, requires a deep and thorough knowledgeof its interaction with the steel surface. The Surface ICP-OEStechnique developed for some years at ARCELOR RESEARCH SA,has permitted to obtain the electrochemical and chemical characterizationof pickling, in real time, up to now on laboratory samples.The principle and the developments of this technique and its transferto pickling are presented. The results obtained in some caseshighlight the potential and the interest of this approach for an improvedcontrol of the pickling process.