To provide a totally safe and highly efficient drying device.

The drying device is provided with a carrying part 12 having a screw for sending out drying targets input from a hopper; an inner cylindrical body 21 rotated around the axis of a cylindrical body which has, on the inner wall, an inner screw 22C for moving the drying targets coming from the carrying part 12 and a plurality of projections 22S linearly extended from an inlet side to an outlet side and an outer screw 31A on the outer wall; an outer surrounding body 31 provided outside the inner cylindrical body 21, internally storing the inner cylindrical body 21 rotatably, and having a heat chamber part 31b for generating hot gas heating the inner cylindrical body 21; burners 34A-34F for overheating the heat chamber part 31b; and an exhaust gas supply means for supplying exhaust gas generated by the burners 34A-34F from a carrying tip part for the drying targets with respect the screw of the carrying part 12.