To provide a method for controlling the heater of a refrigerator with high conduction efficiency in which overcooling of a vegetable compartment is prevented even if the set temperature in the compartment is switched by means of a dial and foods contained in the compartment is protected surely against low temperature trouble.

If the temperature detected by a freezing compartment sensor 14 is lower than a threshold level (S2) and a compressor 9 is turned on (S3), an overcooling preventive heater 8 is turned on (S4). If the temperature detected by the freezing compartment sensor 14 is higher than the threshold level (S5) and the compressor 9 is turned off (S6), the overcooling preventive heater is turned off (S1).