With ever-increasing applications of microelectromechanical systems (MEMS), techniques to measure their micro-movements have become important. This paper presents a new method for amplitude measurement of a vibrating silicon diaphragm using Talbot interferometry. A silicon wafer glued to a speaker diaphragm was initially used as a periodically vibrating test sample. A sinusoidal voltage was applied to the speaker to induce vibrations whose amplitude was measured as a function of frequency. The same technique has further been extended for amplitude measurement of vibration of mechanically excited silicon diaphragm, fabricated using well known "bulk micromachining technology".