This article presents a new approach to measure the fluid velocity using the flow-induced vibration of a microcantilever. The gas flow sensor was fabricated using the microfabrication technology and mounted on a printed circuit board for experimental evaluation. For signal processing, a Wheastone bridge circuit was prepared. The experimental measurement of the fluid velocity was performed in the wind tunnel. The flow-induced vibration of the microcantilever was firstly visualized. Based on the power spectrum analysis, the vibrating frequency was constant at 1.173 kHz, independently of the inlet velocity. It is completely different from the conventional flow-induced vibration proportional to the inlet velocity. The peak-to-peak voltage outputs corresponding to the air velocities of 3, 4, 5 and 6 m/s were measured.