An air conditioner, including a first compressor that compresses refrigerant; a second compressor that compresses the refrigerant; an indoor heat exchanger that performs heat exchange between the refrigerant and air; a first four-way valve connected to the first compressor; a first outdoor heat exchanger connected to the first four-way valve; a first valve connected to the first four-way valve; a second four-way valve connected to the second compressor; a second outdoor heat exchanger connected to the second four-way valve; a second valve connected to the second four-way valve; a first valve pipe that connects the first four-way valve and the second four-way valve; a second valve pipe that connects the first valve and the second valve; and a third four-way valve connected to the first valve pipe, the second valve pipe, the first compressor and the second compressor, and the indoor heat exchanger.