Abstract: The microstructure, of semiconductor material, includes a micromotor and an encapsulation structure. The micromotor is externally delimited by a first and a second faces, opposed to one another, and by a side delimitation trench. The encapsulation structure surrounds the micromotor and has a bottom portion facing the second face of the micromotor, and an outer lateral portion facing the side delimitation trench. An outer separation trench extends through the bottom portion of the encapsulation structure, separates a mobile region from the external side portion, and defines, together with the side delimitation trench, a labyrinthic path for contaminating particles. A sealing ring extends on the bottom portion of the encapsulation structure around an inner separation trench separating the mobile region from a fixed central region and closes a gap between the bottom portion and a mobile component connected to the mobile region of the encapsulation structure.