To provide a centralized control device capable of performing accurate setting while reducing an operator's burden by selecting only an indoor unit which is an object of predetermined setting conditions, and carrying out setting operation to the selected indoor unit, and to provide an air conditioner system equipped with the centralized control device and its control method.

The air conditioner system is constituted by connecting a plurality of indoor units, outdoor units and the centralized control device through a communication line. The centralized control device inputs at least one of retrieval conditions for selecting the indoor unit from the operator, e.g., a setting temperature range, an indoor temperature, an on/off state of an indoor unit power source, an operation mode, an operating timer state, a ventilation amount of the indoor unit, a room arrangement state of a room where the indoor unit is installed, and an angle of a wind direction plate of the indoor unit, extracts the indoor unit coinciding with the retrieval conditions and its operating state from a control table, displaying the operating state of the extracted indoor unit on a display part, and batch-sets change instructions of operation to the indoor unit corresponding to the displayed operating state.