An air conditioner in which a compressor , an outdoor heat exchanger , an expansion valve and an indoor heat exchanger are connected to one another through pipes to configure a ring-shaped refrigerant circuit, an outdoor unit includes the compressor , the outdoor heat exchanger and the expansion valve , an indoor unit includes the indoor heat exchanger , and the outdoor unit and the indoor unit are connected to each other through a liquid-side connection pipe and a gas-side connection pipe to configure the refrigerant circuit, wherein the air conditioner includes a refrigerant charge port provided in a connection valve connected to the liquid-side connection pipe or the gas-side connection pipe , a liquid-side valve provided on the pipe between the liquid-side connection pipe and the expansion valve , and a gas-side valve provided on the pipe between the gas-side connection pipe and the compressor , wherein the air conditioner further includes a pressure detector provided on the pipe from the liquid-side valve to the indoor heat exchanger or the pipe from the indoor heat exchanger to the gas-side valve , a degree of vacuum setting means and comparison means , and a control unit which, in a state where the outdoor unit contains the refrigerant precharged into the pipe of the outdoor unit closed by the liquid-side valve and the gas-side valve , where the liquid-side valve and the gas-side valve are closed, where the outdoor unit and the indoor unit are connected to each other, and where evacuation is carried out by a vacuum pump connected to the opened refrigerant charge port, closes the refrigerant charge port, and opens the liquid side valve and the gas-side valve when the pressure detector detects a predetermined degree of vacuum, wherein, as the evacuation operation is carried out, a detection signal from the pressure detector is sent to the control unit , and the comparison means compares whether a degree of vacuum reaches a value set by the degree of vacuum setting means . the air conditioner includes a refrigerant charge port provided in a connection valve connected to the liquid-side connection pipe or the gas-side connection pipe , a liquid-side valve provided on the pipe between the liquid-side connection pipe and the expansion valve , and a gas-side valve provided on the pipe between the gas-side connection pipe and the compressor , wherein the air conditioner further includes a pressure detector provided on the pipe from the liquid-side valve to the indoor heat exchanger or the pipe from the indoor heat exchanger to the gas-side valve , a degree of vacuum setting means and comparison means , and a control unit which, in a state where the outdoor unit contains the refrigerant precharged into the pipe of the outdoor unit closed by the liquid-side valve and the gas-side valve , where the liquid-side valve and the gas-side valve are closed, where the outdoor unit and the indoor unit are connected to each other, and where evacuation is carried out by a vacuum pump connected to the opened refrigerant charge port, closes the refrigerant charge port, and opens the liquid side valve and the gas-side valve when the pressure detector detects a predetermined degree of vacuum, wherein, as the evacuation operation is carried out, a detection signal from the pressure detector is sent to the control unit , and the comparison means compares whether a degree of vacuum reaches a value set by the degree of vacuum setting means . <EOS>