Abstract: Vacuum heat treatment is widely used by more and more enterprises because of its advantages such as non-oxidation and decarbonization, good comprehensive mechanical properties, high degree of automation, and green and pollution -free. However, due to its high degree of automation and the requirements for sealing the chamber, high requirements are placed on the operator's skills, daily maintenance and the cleanliness of the furnace; this paper studied the causes and harm of pollution in the chamber of gas quenching vacuum furnace. The measures to prevent the pollution of chamber during using the equipment and the daily maintenance were discussed.

Key words: gas quenching furnace, pollution, use, maintenance