Abstract: The invention relates to a device for producing active oxygen ions in the air for improved air quality, comprising at least one air ionizer and an electric transformer producing sufficient electrical high voltage for air ionization. The air ionizer is coupled to a sensor which detects the oxidizable gas content in the air (air pollution sensor). On the basis of the detected content of such oxidizable gases, the electrical energy which is guided to the air ionizer is transformed by an electrical control device in such a way that only low-level ionization occurs at low concentration of oxidizable gases. Said ionization is sensor-controlled and can automatically be increased to a maximum value when the concentration of oxidizable gases rises.