To provide a rotary drum conveyor capable of stably supplying/transporting a dry raw material much in fine powder from a storage place without flushing.

A central shaft 12 and a screw blade 13 erected on this outer periphery are arranged in a cylindrical rotary casing 11. The outer peripheral end of the screw blade 13 is integrally fixed in a state having no clearance with an inner peripheral surface of the rotary casing 11. In an end part of the rotary casing 11, an inlet side end part is rotatably inserted into an inlet side connecting fixed casing 14, and an outlet side end part is rotatably inserted into an outlet part connecting fixed casing 15. The central shaft 12 is projected outward from both ends of the rotary casing 11, and is journaled on one end side, and is connected to a driving source, and is rotatably supported on the outer peripheral side of the rotary casing 11 integrally fixed on the other end side, and is constituted so as to integrally rotate the central shaft 12 and the rotary casing 11 in driving.