This paper presents a basic structure combined with a film and a substrate to investigate the damage and deformation of thin films and to predict the life time of MEMS. The bifurcation and fracture of thin films under a tensive load were determined by an experiment where the film/substrate structure was used as the specimen.The substrate was a deposited aluminium film with different thicknesses of 100,150 and 200 nm. Then the experiment was initiated using our designed loading device. An OLYMPUS microscope was used to observe the change of the topography of the film surface. The destruction of the film and the corresponding sizes of the load and displacement were recorded.Finally,the effects of film thickness on bifurcation and fracture were obtained by comparing experimental results. These show that the relevant rupture strain increases with the film thickness and the crack density along the loading direction depends on the thickness of the film and the failure stain when there are cracks appear on the film surface.