To provide an air-conditioner simultaneously solving the lack of lubricating oil and the reduction of cooling efficiency of a variable capacity compressor.

The air-conditioner has an electromagnetic proportional flow rate control valve 12 consisting a variable orifice in an output side coolant path the variable capacity compressor 1 of flow control by a constant differential pressure valve 13 controlling such that a front and rear differential pressure (PdH-PdL) of a variable orifice becomes constant by flow rate Qd flowing, and a normal charge expansion valve 3. A high cooling efficiency can be maintained even in the time of low load because a coolant at the outlet of an evaporator 4 can be maintained in overheating condition due to the valve 3, a lubricating oil for the compressor 1 does not become short in the time of low load because the electromagnetic proportional flow control valve 12 can control so as to pass a minimum flow of the coolant required for oil circulation by external control signals.