The morphology of gold nanoclusters deposited on the SiO2 surface and irradiated by 200 keV-Ar+ ion beam at room temperature was investigated by atomic force microscopy and transmission electron microscopy. The possibility of controlling the Au clusters size and size distribution by an appropriate choice of the process parameters was demonstrated and, in particular, the effects of ion flux and fluence was studied. The experimental data were modelled by clusters ripening and inverse ripening theory taking into account the sputtering process of the gold atoms from the surface by ion irradiation.