PURPOSE: To eliminate the bottleneck of a working line even in a rice milling plant by providing the rice milling machines to the preceding and following processes of a rice grain humidifier which is constituted by equipping the humidifier to the humidification cylinders, providing the air holes on the surface of an inner hollow screw shaft and interposing a fan in the air duct communicating the insides of the humidification cylinders with the aperture end of a screw.

CONSTITUTION: The grains of rice are firstly worked to polished rice with a rice milling machine in a preceding process and introduced into the humidifica tion cylinders 203A, 203B of a rice grain humidifier 2 and the water fed through a spray nozzle 253 is poured thereon and uniformly impregnated to the insides when they are transferred while being agitated with the screws 204A, 204B. Excess water stuck on the surface of polished rice is almost removed by the wind fed through an air duct 258 but slightly stuck water is removed while the grains of rice are polished by grain friction when the grains are passed through the rice milling machine in the following process. Therefore humidifica tion can be performed in an extremely short time and the bottleneck of the working line is eliminated even in the rice milling plant.