A technique developed for studying the mechanical behavior of nano-scale thin metal films on substrate is presented. The test structure was designed on a novel "paddle" cantilever beam specimens with dimensions as few hundred nanometers to less than 10 nanometers. This beam is in triangle shape in order to provide uniform plane strain distribution. Standard clean room processing was used to prepare the paddle sample. The experiment can be operated by using the electrostatic deflection on the "paddle" uniform distributed stress cantilever beam and then measure the deposited thin metal film materials on top of it. The measured strain was converted through the four step phase-shifting method measurement for the deflection of the cantilever. System performance on the residual stress measurement of thin films were studied with the deflections of silver, gold, and copper films and calculated.