PURPOSE: To make it possible to almost uniform a coating thickness without wastefully consuming a paint, by forming an air jet orifice for injecting an air stream radially toward the peripheral flange part of a rotary disc from the center part thereof along the upper surface of the rotary disc subjected to horizontal rotary drive.

CONSTITUTION: A paint supply port 2 is provided to the center part of a metal rotary disc 1 subjected to horizontal rotary drive at a high speed and a knife edge 3 is formed to the peripheral flange part thereof. In this structure, the thin film of a paint is formed on the paint flow surface 4 of the disc 1 by rotary centrifugal force and the paint is scattered to the radius direction of the disc 1 by high voltage applied between the knife edge 3 of the periperal flange part of the disc 1 and an object 5 to be painted positioned at the lateral side of the disc 1 as well as the disc 1 is slowly drivem upwardly and downwardly. In addition, an air stream is injected radially toward the peripheral flange part of the disc 1 from the center part thereof along the upper surface of the disc subjected to the horizontal rotary drive by an air jet orifice 20 provided to the apparatus. Therefore, the upper end part of the object to be coated can be sufficiently painted and coating thickness is made almost uniform.