Thin poly(methyl methacrylate) (PMMA) films were obtained by casting a polymer solution in chloroform on a glass plate or aluminum foil and solvent evaporation. Next, the PMMA samples on those supports were UV-irradiated using low-pressure mercury vapor lamp emitting 254 nm radiation. The changes in chemical structure of PMMA were monitored by X-ray photoelectron spectroscopy (XPS). Photoinduced changes of the surface morphology were observed using atomic force microscopy (AFM). It was found that the support type and its surface quality has significant influence on the photochemical transformations in the investigated polymer. The high damage of polymeric surface accompanying by the efficient photochemical reactions in macromolecules were found in the case of PMMA placed on an aluminum foil, whereas the glass support exhibited lower effect on the PMMA photodestruction. The different interaction of macromolecules with the support influences indirectly the surface morphology of the UV-irradiated PMMA. (C) 2009 Elsevier B.V. All rights reserved.