tThe atmospheric pressure ambient air and oxygen plasma treatment of flat aluminum sheets using the so-called Diffuse Coplanar Surface Barrier Discharge (DCSBD) were investigated. The main objective of thisstudy is to show the possibility of using DCSBD plasma source to activate and clean aluminum surface. Sur-face free energy measurements, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopycoupled with Energy Dispersive X-ray Spectroscopy (SEM/EDX) and Attenuated Total Reflectance FourierTransform Infrared Spectroscopy (ATR-FTIR) were used for the characterization of the aluminum surfacechemistry and changes induced by plasma treatment. Short plasma exposure times (several seconds) ledto a significant increase in the surface free energy due to changes of its polar components. Various age-ing effects, depending on the storage conditions were observed and discussed. Effects of air and oxygenplasmas on the removal of varying degrees of artificial hydrocarbon contamination of aluminum surfaceswere investigated by the means of EDX, ATR-FTIR and XPS methods. A significant decrease in the carbonsurface content after the plasma treatment indicates a strong plasma cleaning effect, which together withhigh energy efficiency of the DCSBD plasma source points to potential benefits of DCSBD application inprocessing of the flat aluminum surfaces.