PURPOSE: To clean the whole of a substrate conveyor chain including a chain main body and to forcibly remove a cleaning solvent attached on the substrate conveyor chain.

CONSTITUTION: A descending chain part 11a is formed by drawing out an endless type substrate conveyor chain 11 which can be moved in a chain guide 14 on a flux coating line from the chain guide 14 downward. An ascending chain part 11b is bent back upward from the descending chain part 11a and drawn in the chain guide 14. A cleaning tank 21 is provided on the lower side of a bent back part from the descending chain part 11a to the ascending chain part 11b. A cleaning brush 26 to receive supply of a cleaning solvent to the descending chain part 11a is provided, and an air nozzle 27 to jet air against the ascending chain part 11b is provided. The conveyor chain is cleaned by the cleaning brush 26, and the cleaning solvent attached on the conveyor chain is removed by the air jetted from the air nozzle 27 at the ascending chain part 11b and the conveyor chain is dried.