An ice-making machine comprising a box-shaped lower housing provided therein with an ice storage bin, a box-shaped upper housing mounted on a rear portion of the lower housing, an ice-making mechanism assembled within the front portion of a machine compartment formed in the upper housing, and a freezing unit installed behind the ice-making mechanism for supplying refrigerant to the ice-making mechanism, wherein an open-and-close lid is mounted on an opening formed between the lower end of the front face of the upper housing and the upper end of the front face of the lower housing, and wherein an air intake passage is formed to cause outside air introduced from the front face of the lower housing to flow as cooling air into the machine compartment along inner surfaces of one side wall and the rear wall of the lower housing, and an air discharge passage is formed to cause the air after cooling to flow outward along inner surfaces of the rear wall and the other side wall of the lower housing and to discharge to the exterior from the front face of the lower housing.