PURPOSE: To prevent the contamination of an arm part and to arrange hoses by providing a protector having a plurality of through-holes provided thereto in its axial direction to the outer periphery of the arm part in a freely detachable manner and connecting a plurality of the respective hoses connected to a spray gun to a plurality of the through-holes of the protector in a freely detachable manner.

CONSTITUTION: A moving truck 3 positioning and feeding a car body 2 and a painting robot 4 for painting the body 2 are respectively arranged on a booth floor 1. An electrostatic air atomizing type spray gun 6 is provided to the leading end of the arm part 5 of the painting robot 4. The body 2 positioned on the moving truck 4 is subjected to electrostatic painting by the spray gun 6 of the painting robot 4. A high voltage cable 7 applying high DC voltage to the leading end of the spray gun 6, a hose 8 for pattern air, an atomizing air hose 9, an air hose 10 for paint ON/OFF and a paint hose 11 are respectively connected to the spray gun 6 of the painting robot 4 earthed through the truck 3 and the booth floor l through a protector 12. By this method, the contamination of the arm part of the painting robot 4 can be prevented and maintenance properties can be enhanced.