A heater apparatus divides a heater capacity (heater wire), connects the divided heater wire portions to each other outside the a heat insulating layer, changes a connection mode irrespective of which of a 100 V system or a 200 V system is used as a supply voltage, and thereby suppresses a heater temperature to within a safe range even in a continuous current conduction mode, and uses a common heater and suppress management cost. Furthermore, since the heater wire portions are connected to each other outside the heat insulating layer for the heater embedded in the heat insulating layer of a refrigerator, the heater apparatus is capable of reducing production loss due to misconnections and using a common heater.