To manufacture an air conditioner group having heat exchangers with different capacities at a low cost.

This method of manufacturing the air conditioner group having the heat exchangers with different capacities comprises the steps of manufacturing a lower casing, manufacturing indoor heat exchangers, and mounting indoor heat exchanger units. In the step of manufacturing the lower casing, the common lower casing 70 is manufactured. In the step of manufacturing the indoor heat exchangers, multiple types of indoor heat exchangers 50, 57, and 58 having third indoor heat exchangers 50c, 57c, and 58c and fourth indoor heat exchangers 50d, 57d, and 58d vertical to the lower casing 70 supporting the indoor heat exchangers 50, 57, and 58 and in which only the lengths of the third indoor heat exchangers 50c, 57c, and 58c and fourth indoor heat exchangers 50d, 57d, and 58d are different from each other are manufactured. In the step of mounting the indoor heat exchanger units, the indoor heat exchangers selected from among the multiple types of indoor heat exchangers 50, 57, and 58 are mounted on the common lower casing 70.