An aerosol charge neutralizing device simple in structure and easy to maintain, comprising an aerosol passing container that has a conductive material-made tube body constituting an aerosol passing path permitting aerosol to flow therethrough and has an opening pair consisting of openings in pair disposed oppositely across the center line of the tube body and penetrating through the wall surface of the tube body, and insulation tube that has an insulation material-made tube, has a window pair consisting of windows in pair disposed oppositely across the center line of the tube and penetrating through the wall surface of the tube, and is fitted concentrically over the outer surface of the aerosol passing container with the windows coinciding with the openings, a bipolar ionizing element that has a discharge electrode on a dielectric film and is attached to the insulation tube with the windows closed and the discharge electrode exposed to the aerosol passing path, and an outer tube that includes air-tightly the insulation tube and the bipolar ionizing element between it and the aerosol passing container.