PURPOSE: To collect the coating powder scattered about an article to be coated and to improve the coating efficiency, by means of a gas jet unit or corona discharge electrode around the article and the powder spray gun in electrostatic powder coating.

CONSTITUTION: Compressed air is sent from the air compressor 1, through the dehumidifier 2, and, if necessary, air-conditioner 3, air regulator 4, to the gas jet unit 5. The scattered powder coating material is recharged by the high voltage of the same polarity as a spray gun applied to one or plural corona discharge electrodes 8 provided on the gas jet unit to offset the part of weak electric field and to improve the preventing effect of powder scattering. The corona discharge electrodes 8 form an auxiliary field which can be used alone without in combination with the gas jet unit 5. The auxiliary field preferably has an increased field strength within such a range as not to cause inverse ionization.