Abstract: An air atomizing electrostatic coating gun which atomizers a liquid paint by using air flows and thereafter applying atomized liquid paint to an object to be coated by using an electrostatic force. In this coating gun, all of a rod valve, a driving piston, an air cylinder and valve support members of a needle valve device are made of insulating materials having good insulating properties, and an electrode for charging paint particles is attached to the valve. A nozzle-needle valve assembly which is integrally constructed by attaching a paint nozzle to a cylindrical extension of the air cylinder which is formed at a front end portion thereof, is inserted and fitted into a generally cylindrical cavity in a front end portion of the gun body from the front side thereof.