An atomic force microscope (AFM) operating in air has been used to study the growth of evaporated nickel oxide on highly oriented pyrolytic graphite (HOPG) and mica. These substrates show atomically flat surfaces which can be imaged by the AFM with atomic resolution enabling, therefore, a clear identification of the deposit. On HOPG, spherical NiO structures (diameter similar to 100 nm, height similar to 10 nm) are observed to coalesce along the steps. Increasing the evaporation time and once the steps are occupied, a 'dendritic' growth on the terraces is observed. On mica, a more homogeneous distribution of smaller NiO islands is obtained over the whole surface. Nevertheless, a weak adhesion to the substrate is found. The friction AFM images have allowed to establish the relative friction of the materials, which follow the decreasing sequence : graphite, NiO and mica.