An air conditioner is provided. The air conditioner includes two or more heat exchangers, a refrigerant pipe, a compressor, an accumulator, and an overcooler. The heat exchangers perform heat exchanging between air or water and refrigerant. The refrigerant pipe guides refrigerant circulating between the two or more heat exchangers. The compressor compresses refrigerant flowing in the refrigerant pipe to a high temperature and pressure. The accumulator is provided on one side of the compressor, to separate an inflowing refrigerant into a liquid refrigerant and a gaseous refrigerant. The overcooler is provided on one side of the heat exchangers, to further cool refrigerant passing through the heat exchangers.