PURPOSE: To increase production of ice per unit time by turning a blade while touching the inner circumferential surface of an ice making tube to form a uniform thin film of an aqueous liquid flowing downward along the inner circumferential surface of the ice making tube and scraping the ice formed on the inner circumferential surface of the ice making tube.

CONSTITUTION: Inner circumferential surface of an ice making tube 3 is cooled by a refrigeration system 4 and aqueous liquid being fed from a tank 6 to a distributor 5 is sprayed on the inner circumferential surface of the ice making tube 3. The aqueous liquid is cooled to be frozen in the way of flowing down the inner circumferential surface of the ice making tube 3 to form ice thereon. The ice is scraped and contained in the tank 6. Since the ice does not adhere continuously to the tube 3, ice production per unit time is increased. Since the aqueous liquid flowing down on the inner circumferential surface forms a thin film of uniform thickness by means of a blade 72, thermal resistance thereof is made uniform and cooling rate is increased thus shortening the time required for freezing.