A pipe probing method for an air conditioner, the air conditioner including a plurality of dispensers (20, 30) and a plurality of indoor unit groups (50, 60) connected to each of the dispensers (20, 30), comprising: probing the indoor unit groups (50, 60), to which respective dispensers (20, 30) are connected, by operating the indoor unit groups (50, 60) connected to the respective dispensers (20, 30) one by one and detecting the indoor unit group (50, 60) that is operating, wherein the indoor unit groups (50, 60) include a plurality of indoor units (51, 52, 53, 61, 62, 63), respectively and a plurality of valves (21, 22, 23, 31, 32, 33) are arranged on each of the dispensers (20, 30) to flow a refrigerant into and from the indoor units (51, 52, 53, 61, 62, 63); and probing pipes of the dispensers (20, 30), to which respective the indoor units (51, 52, 53, 61, 62, 63) are connected, by operating the indoor units (51, 52, 53, 61, 62, 63) of each indoor unit group (50, 60) one by one and detecting the indoor units (51, 52, 53, 61, 62, 63) that are operating, characterized in that first valves (21, 22, 23, 31, 32, 33) of one dispenser (20, 30) are opened to operate a first indoor unit group (50, 60) and second valves (21, 22, 23, 31, 32, 33) of the other dispensers (20, 30) are closed not to operate the other indoor units (51, 52, 53, 61, 62, 63) when probing indoor unit groups (50, 60), and wherein one valve (21, 22, 23, 31, 32, 33) of the first valves (21, 22, 23, 31, 32, 33) is opened to operate one indoor unit (51, 52, 53, 61, 62, 63) of the first indoor unit group (50, 60) and the other valves (21, 22, 23, 31, 32, 33) of the first valves (21, 22, 23, 31, 32, 33) are closed not to operate the other indoor units (51, 52, 53, 61, 62, 63) of the first indoor unit group (50, 60) when probing pipes of the dispensers (20, 30). probing the indoor unit groups (50, 60), to which respective dispensers (20, 30) are connected, by operating the indoor unit groups (50, 60) connected to the respective dispensers (20, 30) one by one and detecting the indoor unit group (50, 60) that is operating, wherein the indoor unit groups (50, 60) include a plurality of indoor units (51, 52, 53, 61, 62, 63), respectively and a plurality of valves (21, 22, 23, 31, 32, 33) are arranged on each of the dispensers (20, 30) to flow a refrigerant into and from the indoor units (51, 52, 53, 61, 62, 63); and probing pipes of the dispensers (20, 30), to which respective the indoor units (51, 52, 53, 61, 62, 63) are connected, by operating the indoor units (51, 52, 53, 61, 62, 63) of each indoor unit group (50, 60) one by one and detecting the indoor units (51, 52, 53, 61, 62, 63) that are operating, characterized in that first valves (21, 22, 23, 31, 32, 33) of one dispenser (20, 30) are opened to operate a first indoor unit group (50, 60) and second valves (21, 22, 23, 31, 32, 33) of the other dispensers (20, 30) are closed not to operate the other indoor units (51, 52, 53, 61, 62, 63) when probing indoor unit groups (50, 60), and wherein one valve (21, 22, 23, 31, 32, 33) of the first valves (21, 22, 23, 31, 32, 33) is opened to operate one indoor unit (51, 52, 53, 61, 62, 63) of the first indoor unit group (50, 60) and the other valves (21, 22, 23, 31, 32, 33) of the first valves (21, 22, 23, 31, 32, 33) are closed not to operate the other indoor units (51, 52, 53, 61, 62, 63) of the first indoor unit group (50, 60) when probing pipes of the dispensers (20, 30).