As a defrosting means for an evaporator having a combustible refrigerant sealed therein and included in a refrigerating cycle, a plurality of glass tube heaters are installed in the vicinity of the evaporator. And, the electricity passing time or the applied voltage is controlled such that the surface temperature of the glass tube heaters is less than the ignition temperature of the combustible refrigerant. Further, the glass tube heaters and the evaporator fins are brought into contact with each other to lower the surface temperature of the glass tube heaters. Further, the glass tube heaters are of multiple construction and a sealing member is installed on the end surface. With such arrangement, in a refrigerator using a combustible refrigerant, even if defrosting is effected in a combustible refrigerant-leaking environment, firing of the combustible refrigerant can be prevented and so can be non-cooling due to the residue of the frost. |