PURPOSE: To produce ice cubes in a normal size constantly by judging whether the quantity of water in a feed tank is at level sufficient for supplying the rated quantity of water to ice an ice tray.

CONSTITUTION: A float 12a that moves in accordance with changes of the water level is provided to a feed tank 12. As the position of the float 12a descends and reaches a detecting point, the position is detected by the light that is emitted from a water level sensing element 19 and thrown back by the float 12a. Then, a microcomputer 17 judges shortage in remaining quantity of water in the feed tank 12, based on the detection signals of the water level sensing element 19. The water level in the feed tank 12 is detected when the water is fed, and when the judgement is made for shortage of the water necessary for the next feeding, the microcomputer 17 notifies the shortage by lighting up a feeding lamp 27, and the feeding is stopped until the tank is replenished with water. Thereby ice cubes in a normal size can be surely produced.