A novel nanomachining method based on the atomic force microscope (AFM) is presented to process millimeter scale nanochannels on the surface of the aluminum alloy. Effects of the machining parameters including the machining velocity, the normal load and the feed rate on chip formation mechanism and the machined results are investigated. Results show that more and longer continuous belt-type chips are achieved with a higher machining velocity than a lower one because the higher machining velocity will bring more heat which results in a larger adhesion force between removed materials. There is a significant difference of chip states between the light load and the heavy load which is induced by different removal states. The percentage of the ploughing and cutting states with different feed rates in each scratch plays the key role in this method which has a significant effect on the removal chip states as well as the machined depth of the nanochannels. Moreover, relationships between the depths and surface roughness and the machining parameters are provided. Finally, a nanochannels array and a 3D ladder-type channel with a millimeter scale are obtained successfully indicating the capability of fabrication of the millimeter scale nanochannels using this method. (C) 2012 Elsevier B.V. All rights reserved.