The dew point sensor device comprises a semiconductor substrate (1), a Peltier element (2), which may be integrated in the substrate (1), a temperature sensor (3), a capacitor (4) at an exposed surface (9) above the substrate (1) and in the vicinity of the temperature sensor (3), and an electronic circuit (5), which may also be integrated in the substrate (1). The capacitor (4) comprises a plurality of capacitor elements (40) each having a capacitance, and the electronic circuit (5) is provided for an individual determination of the capacitances. The dew point is determined by a measurement of the variation of the capacitances at decreasing temperatures and a measurement of the relevant temperature.