An air conditioner, comprising: a compressor for compressing a refrigerant, the compressor having a high pressure side and a low pressure side; a condenser for condensing the refrigerant compressed at the compressor ; an evaporator for evaporating the refrigerant condensed at the condenser ; and an injection module configured to selectively or simultaneously inject a portion of the refrigerant flowing from the condenser to the evaporator into the high pressure side and the low pressure side of the compressor , wherein the injection module comprises: an injection expansion valve for expanding the portion of the refrigerant; an injection heat exchanger for heat-exchanging and evaporating the portion of the refrigerant expanded at the injection expansion valve with the refrigerant flowing from the condenser ; a high pressure injection valve , disposed between the injection heat exchanger and the high pressure side of the compressor , configured to control the flow of the refrigerant evaporated by the injection heat exchanger ; and a low pressure injection valve , disposed between the injection heat exchanger and the low pressure side of the compressor , configured to control the flow of the refrigerant evaporated by the injection heat exchanger , wherein the injection heat exchanger is connected to the condenser , the injection expansion valve , the high pressure injection valve , and the low pressure injection valve . a compressor for compressing a refrigerant, the compressor having a high pressure side and a low pressure side; a condenser for condensing the refrigerant compressed at the compressor ; an evaporator for evaporating the refrigerant condensed at the condenser ; and an injection module configured to selectively or simultaneously inject a portion of the refrigerant flowing from the condenser to the evaporator into the high pressure side and the low pressure side of the compressor , wherein the injection module comprises: an injection expansion valve for expanding the portion of the refrigerant; an injection heat exchanger for heat-exchanging and evaporating the portion of the refrigerant expanded at the injection expansion valve with the refrigerant flowing from the condenser ; a high pressure injection valve , disposed between the injection heat exchanger and the high pressure side of the compressor , configured to control the flow of the refrigerant evaporated by the injection heat exchanger ; and a low pressure injection valve , disposed between the injection heat exchanger and the low pressure side of the compressor , configured to control the flow of the refrigerant evaporated by the injection heat exchanger , wherein the injection heat exchanger is connected to the condenser , the injection expansion valve , the high pressure injection valve , and the low pressure injection valve . an injection expansion valve for expanding the portion of the refrigerant; an injection heat exchanger for heat-exchanging and evaporating the portion of the refrigerant expanded at the injection expansion valve with the refrigerant flowing from the condenser ; a high pressure injection valve , disposed between the injection heat exchanger and the high pressure side of the compressor , configured to control the flow of the refrigerant evaporated by the injection heat exchanger ; and a low pressure injection valve , disposed between the injection heat exchanger and the low pressure side of the compressor , configured to control the flow of the refrigerant evaporated by the injection heat exchanger , wherein the injection heat exchanger is connected to the condenser , the injection expansion valve , the high pressure injection valve , and the low pressure injection valve . <EOS>