Naked silver nanoparticles supported on SiO2 were prepared in a TEM chamber in order to be directly observed in situ their structural changes at high temperature. Without exposing the samples in air, this method give a possibility to understand the behavior of metal itself without any contamination or oxidation. Melting temperature depression according to the particle size could be observed. (C) 2012 Elsevier B.V. All rights reserved.