An air conditioner comprising: at least one indoor unit; an EHP outdoor unit connected to the at least one indoor unit, and comprising a first compressor driven by the EHP outdoor unit using electric power, and for compressing refrigerant, a first outdoor heat exchanger for heat exchange of a refrigerant, and a first accumulator configured to supply the refrigerant to the first compressor; a GHP outdoor unit connected to the at least one indoor unit, and comprising a second compressor for compressing refrigerant, an engine configured to drive the second compressor through a burned gas, a second outdoor heat exchanger for heat exchange of the refrigerant, and a waste heat exchanger configured to exchange heat with the refrigerant using waste heat of the engine; and a low pressure refrigerant common pipe connecting the first outdoor heat exchanger with the second outdoor heat exchanger and being configured to supply a low pressure refrigerant of the GHP outdoor unit to the EHP outdoor unit; characterized in that: the EHP outdoor unit further comprises a first accumulator connection pipe configured to connect the first outdoor heat exchanger with the first accumulator; and the first low pressure refrigerant common pipe is branched from the first accumulator connection pipe, and connected to the GHP outdoor unit, and is further configured to connect the second outdoor heat exchanger with the first accumulator of the EHP outdoor unit and to supply low pressure refrigerant flowing out of the second outdoor heat exchanger to the first accumulator of the EHP outdoor unit. at least one indoor unit; an EHP outdoor unit connected to the at least one indoor unit, and comprising a first compressor driven by the EHP outdoor unit using electric power, and for compressing refrigerant, a first outdoor heat exchanger for heat exchange of a refrigerant, and a first accumulator configured to supply the refrigerant to the first compressor; a first compressor driven by the EHP outdoor unit using electric power, and for compressing refrigerant, a first outdoor heat exchanger for heat exchange of a refrigerant, and a first accumulator configured to supply the refrigerant to the first compressor; a GHP outdoor unit connected to the at least one indoor unit, and comprising a second compressor for compressing refrigerant, an engine configured to drive the second compressor through a burned gas, a second outdoor heat exchanger for heat exchange of the refrigerant, and a waste heat exchanger configured to exchange heat with the refrigerant using waste heat of the engine; and a low pressure refrigerant common pipe connecting the first outdoor heat exchanger with the second outdoor heat exchanger and being configured to supply a low pressure refrigerant of the GHP outdoor unit to the EHP outdoor unit; a second compressor for compressing refrigerant, an engine configured to drive the second compressor through a burned gas, a second outdoor heat exchanger for heat exchange of the refrigerant, and a waste heat exchanger configured to exchange heat with the refrigerant using waste heat of the engine; and a low pressure refrigerant common pipe connecting the first outdoor heat exchanger with the second outdoor heat exchanger and being configured to supply a low pressure refrigerant of the GHP outdoor unit to the EHP outdoor unit; the EHP outdoor unit further comprises a first accumulator connection pipe configured to connect the first outdoor heat exchanger with the first accumulator; and the first low pressure refrigerant common pipe is branched from the first accumulator connection pipe, and connected to the GHP outdoor unit, and is further configured to connect the second outdoor heat exchanger with the first accumulator of the EHP outdoor unit and to supply low pressure refrigerant flowing out of the second outdoor heat exchanger to the first accumulator of the EHP outdoor unit. to connect the second outdoor heat exchanger with the first accumulator of the EHP outdoor unit and to supply low pressure refrigerant flowing out of the second outdoor heat exchanger to the first accumulator of the EHP outdoor unit.