A flotage trapping device has at least one plus electrode and at least one minus electrode. The plus electrode and minus electrode are alternately disposed. The electrodes trap the flotage floating in the air. Another flotage trapping device has at least one electrode of a single polarity and a space ion generating device for generatingions of polarity opposite to that of the electrode so as to form an ion space around or adjacent the electrode. A flotage repelling device has at least one electrode of a single polarity, and a space ion generating device for generating ions of the same polarity as that of the electrode so as to form an ion space around or adjacent of the electrode.