The adhesion of metal films produced by vacuum evaporation has been measured by drawing a smoothly rounded chrome-steel point across the surface and gradually increasing the load on the point until the film was removed. Results are presented for gold, iron and aluminium. In the cases of iron and aluminium, ageing effects have been observed which vary with the residual oxygen concentration. The differences between the ageing curves are explained in terms of the film structures as obtained by electron microscopy. The results indicate that iron and aluminium are both strongly bonded to the glass by an intermediate oxide layer, whereas gold does not form such a layer and is held by van der Waals forces only.