PURPOSE: To keep the wall of a container at a temperature suitable for condensing and separating sulfur, by equipping the outer wall of the container of an inner cylinder wherein a gas containing sulfur vapor is passed with fins in a continuous separator for sulfur in a gas in case of a small amount of treatment.

CONSTITUTION: The gas 10 containing sulfur vapor is fed from one end of the cooling pipe 1, cooled in the pipe, sulfur is condensed on the wall of pipe, the liquid is made to flow along the sloped wall of the pipe, and taken out from the pipe 11. While the desulfrized gas is discharged from the pipe 12. The blade-shaped fins 2 on the outer wall of the pipe 1 promote the heat transfer of the outer wall, so that the temperature of the wall of the pipe is made close to the temperature of a cooling gas which is brought into contact with the outer wall. The temperature of the gas is regulated to about 120W180°C suitable for condensing and separating sulfur. Namely, the cooling gas is passed through the pipe 20 and introduced into the space between the pipe 1 and the outer cylinder 3, the heat of the gas in the pipe 1 is absorbed and the temperature is raised, and the gas is passed through the pipe 21, and circulated through the pipe 20 by the blower 7. The heated gas is cooled by blending it with atmospheric air which is sucked properly from the pipe 22, and the amount of suction of the air is adjusted by the release degree of the controlling valve 6.