Thin films are used in a wide variety of applications such as microelectromechanical system sensors and electronic devices. In particular, tungsten (W) is used as a gate material for semiconductor memory devices. The nanomechanical properties of thin films often deviate from those of their macroscopic status; hence, measurement techniques suitable for their characteristic length scale are required. This study aims to investigate the mechanical properties of nanoscale W thin films using microcantilever resonance testing. The change in the natural frequency of the microcantilever upon W film deposition was measured optically using an ultrasonic generator and a Michelson interferometer. The results show that the proposed technique can effectively evaluate the nanomechanical properties, overcoming the drawbacks of traditional contact mechanics-based methods.