PURPOSE: To enable the preparation of dried Tofu (bean curd) having high quality with a small energy loss, by cooling and dehymidifying air having absorbed moisture in a drying chamber by a heat exchanger at the evaporator side of a heat pump in a circulating hollow part, heating it by a heat exchanger at a condenser side, making it flow through the drying chamber.

CONSTITUTION: In a closed type dryer surrounded by a double wall, the outer wall 1 consists of a heat insulating material, the inner wall 2 consists of a porous plate, and a circulating hollow part for circulating air through the space between the outer wall 1 and the inner wall 2 is set. The floor and the ceiling of the drying chamber surrounded by the inner wall 2 consist of the face 8 to absorb and to release radiation so that the drying chamber can be heated or cooled. The heat exchanger 4 at the steam side of a heat pump is set on the wind of the circulating hollow part above the face 8 to absorb and to release radiation, the heat exchanger 5 at the condensation side of the heat pump is set on the lee, and the circulating fan 6 and the humidifying device 7 are provided further in the circulating hollow part. Consequently, the energy loss is reduced, and high-quality dried Tofu can be prepared.