Micro-Raman spectroscopy was applied to the characterization of the chemical composition and topography of protective oxide layers formed under atmospheric conditions on the surface of thin chromium films. Strips of the layers were produced by local thermal heating using focused sub-picosecond pulsed laser radiation. It is shown that a CrO2 layer is initially formed on the chromium surface at low light exposures. Increasing the exposure results in the transformation of the CrO2 layer to Cr2O3. The influence of the etching conditions on the composition and thickness of the oxide layers is investigated. The topography of the CrO2 and Cr2O3 oxide layers in transverse sections of the strips is demonstrated by the Raman mapping. Copyright © 2011 John Wiley & Sons, Ltd.