cooler unit or by partially introducing the cold airs from the main cooler unit 104 furthermore although both of the main cold air flow channels 106 and the auxiliary cold air flow channels 206 are disposed at the bottom of the storage chamber 3 in the illustrated embodiments they may alternately be disposed to the ceiling or on one side of the storage chamber 3 provided that both of the flow channels 106 and 206 are situated on an identical plane and the main recycling cold air flows and the auxiliary recycling cold air flows are circulated to an identical direction furthermore although no particular explanations have been made in the illustrated embodiments in the case where the perishable foods loaded within the storage chamber 3 are vegetables and fruits that evaporize the after ripening ingredients such as ethylene or aldehydes it is also possible to dispose a layer of a freshness reserving agent that absorbs adsorbs or decomposes these after ripening ingredients to the recycling channel of the cold air preferably to the recycling channel of the cold air flows in which the main recycling cold air flows and the auxiliary recycling cold air flows are joined and returned from the storage chamber 3 to the machine room 5 whereby the concentration of the after ripening ingredients can be reduced and the freshness of the vegetables and fruits can be maintained.