Morphological evolution of thin metallic films, i.e. beading, Ostwald-ripening and/or evaporation of a beaded film, on a substrate under annealing is a complex process which depends on several parameters. However, under accurate experimental conditions, it is possible to study the growth of voids in thin continuous films (beading) separately. We compared different models describing this process and found that the Brandon and Bradshaw's description can be applied for these measurements. They suggest that the voids grow by surface self-diffusion of the metal atoms, independently of the substrate. Hence, from the time dependence of the uncovered surface, which is proportional to the area of voids, the surface self-diffusion coefficient of the metal can be derived. We present here a new method, based on Auger electron spectroscopy and atomic force microscopy techniques, to perform these measurements and we discuss its advantages and limits on an experimental example. (C) 2003 Elsevier Science B.V. All rights reserved.