PURPOSE: To eliminate leak due to dew generated in a cold air circulating path, reduce heat loss and improve refrigerating load by a method wherein a fan is installed in the cold air circulating passage and the fan is operated by the high-pressure air of a compressor.

CONSTITUTION: Partitioning plates 3 are arranged on the internal wall of a refrigerating showcase box body 2 to form a storage chamber 5 and a cold air circulating passage 8, in which a cooler 6 and a cold air circulating fan 7 are installed, while a condenser 9 and a compressor 10, which constitute a refrigerating cycle together with the cooler 6, are provided separately. A ventilating device is constituted of the fan 7 and an air compressor 14, sending high-pressure air from an unit chamber, while the fan is provided with an inflow port 15 and a discharging port 16 and is constituted of a cylindrical. housing 17, an impeller 19 fixed to a rotary shaft 18 and a cold air circulating fan 22 while high-pressure air of the air compressor 14 flows into the impeller 19 through the inflow port 15 to rotate the impeller 19. Heat, generated between the rotary shaft 18 and a bearing 26, reduces heat loss of circulating cold air.