AIR CONDITIONER

PROBLEM TO BE SOLVED: To provide an air conditioner that can perform heating operation and that does not easily start defrosting operation and suppresses a decrease in heating capability by lowering a compressor discharge temperature by making high-temperature refrigerant gas flow in an outdoor heat exchanger and raising an outdoor heat exchanger temperature since heating capability is easily secured as a discharge refrigerant temperature becomes high during the heating operation when a refrigerant which is apt to rise in discharge temperature is used.SOLUTION: An air conditioner which includes a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve and can perform at least heating operation uses a refrigerant which is apt to rise in discharge temperature, and is provided with a bypass circuit which connects a discharge side of the compressor and an in-heating-operation entrance side of the outdoor heat exchanger to each other, the by-pass circuit including a bypass solenoid valve and a bypass expansion value.