PURPOSE: To obtain a normal-temperature, constant-humidity dryer capable of uniformly dehumidifying and drying items charged, such as grains, beans and the like.

CONSTITUTION: Grain is poured into upper and lower drying hoppers 3 and 4 arranged in a dryer silo 2 in turn, and dehumidifying air A having a normal temperature and a constant humidity is supplied to the upper and lower drying hoppers 3 and 4 from a dehumidifying dryer (DAG) to dehumidify and dry line grain charged up to an adequate moisture content. The grain dried is discharged from the lower drying hopper 4 and supplied to a succeeding process such as a refining process, rice cleaning process or storage process. As the grain is dehumidified and dried by the dehumidified air A having a normal- temperature and constant-humidity, the grain is completely prevented from being broken at the body and losing its brightness during drying process, and the quality and commodity value of the grains is certainly prevented from being spoiled. The grain discharged from the lower drying hopper 4 is poured into the upper hopper 3 again to repeat dehumidifying and drying several times until an adequate moisture content is obtained or to store the grain after humidified and dried.