A coater for coating a coating object by spraying paint from a nozzle in an ink-jet fashion, the coater comprising: a nozzle head unit having a nozzle head formed with a plurality of nozzles at a nozzle spray surface and a nozzle driving mechanism causing the paint to be sprayed from the nozzles; a robot arm having a plurality of arms (24, 25, 26) capable of relatively rotating via shafts and an arm driving mechanism (M1 - M6) for moving the arms, and configured to move the nozzle head unit in a state of holding the nozzle head unit through driving of the arm driving mechanism (M1 - M6); and a coating control unit (70; 80; 90; 100; 110) configured to control driving of the nozzle driving mechanism and driving of the arm driving mechanism (M1 - M6) to execute coating on the coating object; wherein the coating control unit (70; 80; 90; 100; 110) controls the execution of the coating on the coating object by repeating scanning of the nozzle head unit for a plurality of times in a state of being divided into segmented coating surfaces formed by each scanning of the nozzle head unit; and wherein the coating control unit (70; 80; 90; 100; 110) performs the coating by forming a normal coating region and an overlapping coating region (CR2; CR21; CR22) in the segmented coating surfaces, wherein the coating is performed in the normal coating region so as to have a target coating film thickness, and the coating is performed in the overlapping coating region (CR2; CR21; CR22) in a state where a spray amount of the paint is reduced compared to the normal coating region; wherein the coating control unit (70; 80; 90; 100; 110) performs an overlapping coating control by mixing the overlapping coating region in the segmented coating surface to be coated in a next scan with the overlapping coating region (CR2; CR21; CR22) in the segmented coating surface coated in a previous scan and taking the coating film thickness of the mixed overlapping coating region (CR2; CR21; CR22) as the target coating film thickness to perform coating; and wherein in the overlapping coating control, the coating is controlled by arranging a plurality of subdivided coating regions (CR4; CR41; CR42) in the overlapping coating region (CR2; CR21; CR22) and by placing the subdivided coating regions (CR4; CR41; CR42) in the overlapping coating region formed in the previous scan adjacent to the subdivided coating regions (CR4; CR41; CR42) in the overlapping coating region (CR2; CR21; CR22) formed in the next scan. a nozzle head unit having a nozzle head formed with a plurality of nozzles at a nozzle spray surface and a nozzle driving mechanism causing the paint to be sprayed from the nozzles; a robot arm having a plurality of arms (24, 25, 26) capable of relatively rotating via shafts and an arm driving mechanism (M1 - M6) for moving the arms, and configured to move the nozzle head unit in a state of holding the nozzle head unit through driving of the arm driving mechanism (M1 - M6); and a coating control unit (70; 80; 90; 100; 110) configured to control driving of the nozzle driving mechanism and driving of the arm driving mechanism (M1 - M6) to execute coating on the coating object; wherein the coating control unit (70; 80; 90; 100; 110) controls the execution of the coating on the coating object by repeating scanning of the nozzle head unit for a plurality of times in a state of being divided into segmented coating surfaces formed by each scanning of the nozzle head unit; and wherein the coating control unit (70; 80; 90; 100; 110) performs the coating by forming a normal coating region and an overlapping coating region (CR2; CR21; CR22) in the segmented coating surfaces, wherein the coating is performed in the normal coating region so as to have a target coating film thickness, and the coating is performed in the overlapping coating region (CR2; CR21; CR22) in a state where a spray amount of the paint is reduced compared to the normal coating region; wherein the coating control unit (70; 80; 90; 100; 110) performs an overlapping coating control by mixing the overlapping coating region in the segmented coating surface to be coated in a next scan with the overlapping coating region (CR2; CR21; CR22) in the segmented coating surface coated in a previous scan and taking the coating film thickness of the mixed overlapping coating region (CR2; CR21; CR22) as the target coating film thickness to perform coating; and wherein in the overlapping coating control, the coating is controlled by arranging a plurality of subdivided coating regions (CR4; CR41; CR42) in the overlapping coating region (CR2; CR21; CR22) and by placing the subdivided coating regions (CR4; CR41; CR42) in the overlapping coating region formed in the previous scan adjacent to the subdivided coating regions (CR4; CR41; CR42) in the overlapping coating region (CR2; CR21; CR22) formed in the next scan.