PURPOSE: To simplify a wiring for indicating defrosting when a plurality of freezing and refrigerating showcases having different defrosting cycles are installed.

CONSTITUTION: A plurality of freezing and refrigerating showcases 1a, 1b-1n are provided with defrosting heaters 2a, 2b-2n and control circuits 7a, 7b7n respectively. The plurality of control circuits are connected to a defrosting indicating device 11, setting the defrosting cycles of all of the showcases, through one piece of signal transmitting wire 12 to output a starting and/or a finishing signal of defrosting from the defrosting indicating device 11 to the control circuits 7a, 7b-7n of respective freezing and refrigerating showcases 1a, 1b-1n. When the signal is specified that the signal is for said freezing and refrigerating showcases 1a, 1b-1n, the conduction of electric current through the defrosting heaters 2a, 2b-2n of said freezing and refrigerating showcases 1a, 1b-1n is put ON or OFF.