To provide a powder roaster in which the deposition of powder in a kiln or on an agitating plate, or the agglomeration of the powder is prevented.

This heater is provided with a cylindrical kiln 2, a gas burner 3 for heating the kiln 2, the gear mechanism 12 and reduction-gear mechanism 13 for rotating the kiln 2 by an electric motor 4 and the opening 36 and closing plate for supplying the powder being a raw material to the flat plate 33 of the kiln 2. An opening for discharging the heated powder, a movable shutter 34 and a fixed plate 35 are furnished to the flat plate of the kiln, a second rotating shaft 16 extending in the direction of the center of rotation of the kiln is formed in the kiln 2, plural agitating plates 18 for agitating the powder are provided to the second rotating shaft 16, and at least any of the agitating plates 18 is used as a movable agitating plate 22 with the angle changeable with a mounting shaft extended orthogonally to the rotating shaft as the center. A third rotating shaft 19 for changing the direction of the movable agitating plate 22 and gears 20 and 21 are furnished in the second rotating shaft 16, and an electric motor 24 for driving the third rotating shaft 19 and gears 20 and 21 and gears 23 and 25 are provided on the second rotating shaft 16.