PURPOSE: To decrease the sticking of dust by subjecting an automotive body to a basic treatment consisting of a pretreatment, primer coating, intermediate coating and finish coating then to treatments including sealing, fusible insulator setting, undercoating, etc.

CONSTITUTION: The automotive body is subjected to the basic treatment consisting of the pretreatment, primer coating, intermediate coating and finish coating and is then subjected to the ancillary treatments consisting of the sealing and fusible insulator setting for the purpose of water-proofing, dust-proofing and rust prevention as well as the undercoating for the purpose of sound insulation, vibration-proofing and rust prevention. The basic treatment from the pretreatment to the finish coating is finished continuously at one time and therefore the sticking of the dust which is liable to be proportional to the exposure time is considerably decreased. Since the ancillary treatment including the sealing, insulation setting, undercoating, etc. where there are many chances for dust sticking is executed after the end of the above-mentioned basic treatment, the sticking of the dust is extremely little.