The present invention relates to a device and method for determining the pollution status of a particle filter (10) for an air-cleaning device (1) with increased accuracy at low extra costs. The device comprises a sheet resistance input (43) for obtaining sheet resistance information (21) indicating or allowing to determine an electrical sheet resistance of the particle filter (10); a humidity input (44) for obtaining humidity information (31) indicating the relative humidity of the filter's environment; and a processor (45) for comparing the electrical sheet resistance indicated by or determined from the obtained sheet resistance information (21) with a reference sheet resistance of a clean particle filter at the relative humidity (31) indicated by the obtained humidity information and given at the time of acquisition of said electrical sheet resistance and for generating, based on said comparison, a control signal (41) for control of the air-cleaning device and/or a status information (42) indicating the pollution status of the particle filter (10).