An air conditioner comprising an outdoor unit including a plurality of compressors (3a, 3b, 3c) in which lubricating oil is stored, and a plurality of indoor units (2A, 2B, 2C) in which a refrigerant circulates to and from the outdoor unit, and configuring a refrigerating cycle by the outdoor unit and the indoor units (2A, 2B, 2C), the air conditioner comprising: a main inlet refrigerant pipe including a plurality of refrigerant inlet pipes (18a, 18b, 18c) connected to inlet portions of the compressors (3a, 3b, 3c); a plurality of oil balancing pipes (30a, 30b, 30c) extracting the lubricating oil stored in each of the compressors (3a, 3b, 3c) in which a specified amount of the lubricating oil or more is stored, the oil balancing pipes (30a, 30b, 30c) comprising ends connected to the compressors (3a, 3b, 3c); an oil storage capsule to which other ends of the oil balancing pipes (30a, 30b, 30c) are connected, and in which the lubricating oil flowing through the oil balancing pipes (30a, 30b, 30c) joins; an oil balancing guide pipe, a distributor connected to the oil storage capsule via the oil balancing guide pipe, the distributor comprising a plurality of outflow ports (Rf, Rg, Rh) to which the lubricating oil led from the oil balancing guide pipe is equally distributed; and a plurality of oil return pipes (55, 56, 57) connecting the outflow ports (Rf, Rg, Rh) and the refrigerant inlet pipes (18a, 18b, 18c) of the main inlet refrigerant pipe to lead the lubricating oil distributed to the outflow ports (Rf, Rg, Rh) of the distributor to the compressors (3a, 3b, 3c), wherein the main inlet refrigerant pipe comprises a horizontal portion extending along the installation surface of the compressors (3a, 3b, 3c), and the distributor is fixed to the horizontal portion of the main inlet refrigerant pipe in a horizontal attitude. a main inlet refrigerant pipe including a plurality of refrigerant inlet pipes (18a, 18b, 18c) connected to inlet portions of the compressors (3a, 3b, 3c); a plurality of oil balancing pipes (30a, 30b, 30c) extracting the lubricating oil stored in each of the compressors (3a, 3b, 3c) in which a specified amount of the lubricating oil or more is stored, the oil balancing pipes (30a, 30b, 30c) comprising ends connected to the compressors (3a, 3b, 3c); an oil storage capsule to which other ends of the oil balancing pipes (30a, 30b, 30c) are connected, and in which the lubricating oil flowing through the oil balancing pipes (30a, 30b, 30c) joins; an oil balancing guide pipe, a distributor connected to the oil storage capsule via the oil balancing guide pipe, the distributor comprising a plurality of outflow ports (Rf, Rg, Rh) to which the lubricating oil led from the oil balancing guide pipe is equally distributed; and a plurality of oil return pipes (55, 56, 57) connecting the outflow ports (Rf, Rg, Rh) and the refrigerant inlet pipes (18a, 18b, 18c) of the main inlet refrigerant pipe to lead the lubricating oil distributed to the outflow ports (Rf, Rg, Rh) of the distributor to the compressors (3a, 3b, 3c), wherein the main inlet refrigerant pipe comprises a horizontal portion extending along the installation surface of the compressors (3a, 3b, 3c), and the distributor is fixed to the horizontal portion of the main inlet refrigerant pipe in a horizontal attitude.