To obtain a cylinder dryer in which lowering of heating efficiency and fluctuation of heating are prevented by discharging drain generated in the cylinder dryer quickly.

A cylinder dryer 1 is provided with a vapor supply opening 3 and a siphon tube 5. The vapor supply opening 3 is coupled through an ejector 10 with a vapor supply pipe 6. The siphon tube 5 is conducted, on the outlet side thereof, with a drain storing section 9 coupled, at the upper part thereof, with the suction chamber 14 of the ejector 10 through an interconnecting path 13. The drain storing section 9 is coupled, at the lower part thereof, with a steam trap 15. Drain standing on the inner wall face of the dryer 1 flows through the opening 4 into the drain storing section 9, flushing vapor is sucked into the ejector 10 and drain is discharged from the steam trap 15 to the outside.