A rotary atomizing head (100, 200, 300) for an electrostatic coater, including an assembly of an atomizing head body and a structural component, wherein the atomizing head body has an inner circumferential surface on which paint, when discharged from the structural component, flows under the centrifugal force, and wherein the structural component is accessible from the front of the atomizing head body to be removably fixed in a central concavity formed in the central portion of the atomizing head body, said structural component comprising: a front wall forming a disc-shaped hub contiguous to the inner circumferential surface of the atomizing head body; a plurality of paint discharge openings formed at circumferentially regular intervals in an outer circumferential surface of the front wall; a plurality of cleaning openings formed in the central portion of the front wall; a side wall extending rearward from the outer circumferential surface of the front wall to be circumferentially continuous; a plurality of legs extending rearward from the outer circumferential surface of the rear end of the side wall; a pawl protruding outwardly from the rear end of each leg into a circumferential recess formed in a circumferential wall of the central concavity for engagement on a side wall of the central concavity; a bottom wall disposed radially inside the plurality of legs; a spoon-cut recess formed in the bottom wall; and a salient formed on an outer circumferential portion of the front end surface of said structural component, the salient acting as a dam mechanism for receiving paint flowing out of the paint discharge openings and spreading it thin and wide, wherein the salient forms a first shoulder on the front surface of the structural component, and a second shoulder is formed on the inner circumferential surface of the atomizing head body 2 to be next to the salient and the atomizing head body. a front wall forming a disc-shaped hub contiguous to the inner circumferential surface of the atomizing head body; a plurality of paint discharge openings formed at circumferentially regular intervals in an outer circumferential surface of the front wall; a plurality of cleaning openings formed in the central portion of the front wall; a side wall extending rearward from the outer circumferential surface of the front wall to be circumferentially continuous; a plurality of legs extending rearward from the outer circumferential surface of the rear end of the side wall; a pawl protruding outwardly from the rear end of each leg into a circumferential recess formed in a circumferential wall of the central concavity for engagement on a side wall of the central concavity; a bottom wall disposed radially inside the plurality of legs; a spoon-cut recess formed in the bottom wall; and a salient formed on an outer circumferential portion of the front end surface of said structural component, the salient acting as a dam mechanism for receiving paint flowing out of the paint discharge openings and spreading it thin and wide, wherein the salient forms a first shoulder on the front surface of the structural component, and a second shoulder is formed on the inner circumferential surface of the atomizing head body 2 to be next to the salient and the atomizing head body.