PURPOSE: To interrupt a high frequency generating circuit when the door of a refrigerating room is opened even upon occurrence of abnormality by comprising a refrigerator of a defrosting room disposed in a refrigerating room, a high frequency generator disposed on the outside of the refrigerating room, and a switch disposed at the door part of refrigerating room and interlocked with opening/closing of the door to open/close a contact.

CONSTITUTION: A high frequency generating circuit 23 is connected through the (b) contact of a refrigerator door switch with a power supply 9 and if a defrost switch 22 is turned on when a refrigerator door 2d is closed, power us supplied to a high frequency generator 20 through a high voltage transformer 19 to generate high frequency wave. It is introduced through a waveguide 6 to a defrost room 4 and chilled foods therein are irradiated with high frequency wave and defrosted. When a refrigeration room door 2a is opened, contact of a refrigeration room door switch 16 is turned to normal open side (a) to interrupt the circuit 23 thus stopping defrost operation. According to the arrangement, the circuit 23 can be interrupted upon opening the door 2a even when the contact of door switch 21 is fused.