In a multiple type air conditioner system which includes a plurality of outdoor units and a plurality of indoor units, the plurality of outdoor units are connected with the plurality of indoor units through a communication line, address setting is attained by generating a random address from each of all the indoor units under a command of one of the outdoor units and generating a dummy address from each outdoor unit on the basis of the random address, by obtaining a correlative relationship between the outdoor and indoor units on the basis of a variation of a physical quantity of the outdoor unit connected to the indoor unit actually operated based on the dummy address, and by updating the addresses of all the outdoor and indoor units on the basis of the correlative relationships between all the outdoor and indoor units obtained through the step.