An ultra-thin MgO film of two monolayers (ML) was successfully grown onto Ag(111) by repeating twice RT adsorption of Mg atomic monolayer, RT oxidation and 725K thermal annealing under UHV conditions. Using Auger electron spectroscopy, low electron energy diffraction and scanning tunneling microscopy/spectroscopy, we report here formation of MgO(1x1) and MgO(1x1)-R30 epitaxial layers, consistent with the growth of a MgO(111) polar film onto the silver surface and composed of patches having extended slight corrugation oriented along defined directions with respect to the substrate. (C) 2015 Elsevier B.V. All rights reserved.