[en] The invention deals with a multipactor discharge apparatus which can be used for tuning microwave organs such as magnetron oscillators and other cavity resonators. This apparatus is suitable for delivering an improved tuning effect in a resonation organ wherefrom the working frequency must be set. This apparatus is equipped with two multipactor discharge electrodes set in a configuration such to that a net current flows from one electrode to another. These electrodes are parallel and flat. The apparatus can be used in magnetron devices as well for continuous waves as for impulses