We present a novel approach for hydrogen gas detection, based on palladium-coated micromechanical resonators. A sequence of thin film technniques allows the large-scale parallel fabrication of free-standing beams separated from a counter-electrode by a mesoscopic air gap. The readout principle has been confirmed. The device manifests a resonance frequency drop from 6.5 to 3 MHz as it is exposed to 4 % of H2 during 15s. The sensor responds within a few seconds to hydrogen gas and has a power consumption of about 10 pW. Preliminary results suggest that this technique can detect very minute concentrations.