This drying/carbonizing device is formed from providing within a drying chamber: a plurality of tubes, to one end of which an inlet is formed and to the other end of which an outlet is formed, of which the upper and lower ends are interconnected to each other to form a single chain, and which have rotatable screw conveyers therewithin that are disposed in a manner so that the outward paths and return paths vertically alternate; horizontal tubes that are attached at appropriate intervals along the lengthwise direction of the plurality of tubes and that are horizontal discharge tubes connected to the plurality of tubes; vertical tubes that are connected to the ends of the horizontal tubes and that are provided in the vertical direction; and a bottom collection tube that is provided horizontally to the bottom, links the ends of the vertical tubes, and removes gas.