PURPOSE: To obtain a grainy material heat-processing rotary kiln which is capable of uniformly roasting grainy material like sesame seeds or peanuts and is prevented from producing a stink caused by ignition and burning of falling dust.

CONSTITUTION: Inside a drum/where far infrared heaters 3 are attached on the inner wall attached is a rotary netted drum 2 to accommodate grainy material. An automatic discharging device 8 such as a screw conveyer is installed beneath the netted drum 2 to discharge falling dust outside the drum 2.