A micromechanical filter having planar components, and manufacturable using very large scale integrated circuit microfabrication techniques. The input and output transducers are interdigitated comb electrodes. The mechanical coupling between the input and output transducers includes planar flexures, displacement of the electrodes producing bending of the elements of the flexures. By sealing micromechanical filters in a vacuum and providing on-board circuitry, high signal-to-noise ratios and quality factors are achievable. Construction of a real-time spectrum analyzer using many micromechanical resonators, provides a device with high accuracy and a short sample time.