The electrostatic spray gun has a cylindrical body (3) with the circular outlet duct (13) for the powder around a conical insert. An outer cylindrical sleeve (21) over the gun provides a circular air curtain directed at the workpiece. The air gun prevents the charged powder particles from deflecting sideways to the control electrodes (16) around the gun. The central insert has a porous structure through which a compressed airflow flushes the outer surface of the gun to prevent the build-up of powder deposits.
