The carbon nanotube (CNT) probe, where a multi-walled (MW) CNT is attached onto the tip apex of a commercial silicon nitride cantilever, is applied to study friction on the nanometer scale using contact atomic force microscope (AFM). The friction versus load curve using CNT tip shows a completely different behavior front that of conventional tip, which is ascribed to the unique shape of CNT. In addition, strong scanning length dependency of the friction force is found due to the deformation of CNT. (C) 2002 Elsevier Science B.V. All rights reserved.