an integrated capacitive - type humidity sensor formed in a semiconductor chip integrating a sensing capacitor and a reference capacitor . each of the sensing and reference capacitors have at least a first electrode and at least a second electrode , the first and second electrodes of each of the sensing and reference capacitors being arranged at distance and mutually insulated . a hygroscopic layer extends on the sensing and reference capacitors and a conductive shielding region extends on the reference capacitor but not on the sensing capacitor .