The invention relates to a helix resonator used in particular in filters operating at radio frequency. In instances in which conventional procedures based on adjusting the resonance frequency are not sufficient for tuning the resonator, the procedure of the invention can be used in which the resonator is tuned by adjusting the distance of the ground plane (the wall of the resonator cover (1)) from a leg (4) of the resonator or a lead (3), usually a micro strip, with which the resonator has been connected to an external circuit or to another resonator.