A microelectromechanical sensor that in one embodiment includes a supporting structure, having a substrate and electrode structures anchored to the substrate; and a sensing mass, movable with respect to the supporting structure so that a distance between the sensing mass and the substrate is variable. The sensing mass is provided with movable electrodes capacitively coupled to the electrode structures. Each electrode structure comprises a first fixed electrode and a second fixed electrode mutually insulated by a dielectric region and arranged in succession in a direction substantially perpendicular to a face of the substrate.