A method for measuring the humidity of a laundry mass contained in a laundry treatment chamber of a laundry appliance. The method includes: providing a capacitor in the laundry appliance, the capacitor having, as part of the capacitor dielectric, the laundry mass; measuring a capacitance of the capacitor by means of an electronic circuitry electrically supplied by a supply voltage and a reference voltage. Providing a capacitor comprises: providing in the laundry appliance at least one conductive plate which forms a plate of the capacitor, and exploiting, as a second plate of the capacitor, routing lines distributing inside the laundry drying appliance the reference voltage.