To stably maintain comfortability by air-conditioning of respective rooms by a plurality of refrigerating cycles which independently air-condition a plurality of cabins.

This air-conditioner is equipped with a first refrigerating cycle 9 which air-conditions a ground floor cabin 10, second refrigerating cycles 19 and 29 which air-condition a second floor cabin 20, and a distribution controlling device 60 which distributes a refrigerant circulating in either one from the second refrigerating cycles 19 and 29 into the first refrigerating cycle 9 when a thermal load in the ground floor cabin 10 has exceeded the air conditioning capacity value of the first refrigerating cycle. Thus, the refrigerant which circulates in a plurality of the refrigerating cycles which independently air-condition the ground floor cabin 10 and the second floor cabin 20 can properly be distributed in response to the thermal loads of both cabins 10 and 20 by the operation of the distribution controlling device 60. Therefore, the comfortability by the air-conditioning of respective cabins can stably be maintained.

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