An air cleaning apparatus having an electrical dust collecting section has discharge electrodes, electrical field forming electrodes arranged parallel to the flow of charged particles, and dust collecting electrodes each of which is arranged between corresponding two adjacent electrical field forming electrodes to be parallel thereto. One high voltage power source is arranged to generate a potential difference between the discharge electrodes and the dust collecting electrodes. Another high voltage power source is arranged to generate a potential difference between the electrical field forming electrodes and the dust collecting electrodes. Negative electrodes consisting of either the electrical field forming electrodes or the dust collecting electrodes are covered by insulator members.