Due to the UV radiation properties such as high surface adsorption and high photon energies, excimer laser are well adapted for surface treatment. UV laser irradiation of a surface with a fluence high enough induces the ejection of particles from the surface (through ablation process). In many cases, laser treatment results are more complex than simple ablation. We studied the effects of excimer laser (XeCl) irradiation of steel surface on its chemical properties. To investigate the induced surface changes, we have used Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). XPS and AES analyses show that the laser treatment induces the apparition of a Fe2O3 layer at the surface instead of FeOOH for an untreated surface. The evolution of the chemical properties of the surface has been studied as a function of the air exposure duration after the laser treatment. (C) 2002 Elsevier Science B.V All rights reserved.