Non-contact AFM imaging was used to investigate the response of a material at small scales during nanoindentation. The true residual area measured from the AFM images can subsequently be used to recalculate the hardness of the material measured by nanoindentation more accurately. In this study, nanoindentation with non-contact AFM has been used to investigate the mechanical properties of thin CN films deposited by rf magnetron sputtering on silicon (100) substrates. Hardness was determined at different loads and depths from nanoindentation using the Oliver and Pharr method. The indents were imaged using AFM and true residual contact areas as well as hardness values were determined. Hardness values obtained by AFM agreed with the hardness measured by the Oliver and Pharr method. (C) 2004 Elsevier B.V. All rights reserved.