Both the processes of adsorption of double‐stranded DNA and its desorption from the surface of freshly cleaved mica can be studied thanks to the Scanning Force Microscope (SFM). The adsorption can be investigated under different conditions with methods ranging from the simple count of adsorbed DNA molecules to the more elaborate study of the local curvature of the adsorbed DNA chains: this high‐resolution information is shedding light on the process of structure‐dependent DNA adsorption on crystal surfaces. SFM‐based Single‐Molecule Force Spectroscopy is very useful for studying the desorption process of DNA from the same surfaces, with the same level of environmental control. © 2003 American Institute of Physics