An air conditioning system (1) includes indoor units (A1, A2), an outdoor unit (B), and a control device (3). The control device (3) is independent of the indoor units (A1, A2) and the outdoor unit (B), and indoor unit control sections (41, 42) and an outdoor unit control section (43) are respectively loaded as virtualized processors. The indoor unit control sections (41, 42) and the outdoor unit control section (43), which are respectively loaded as virtual CPUs onto the control device (3), acquire information from sensors (20) via a common bus (5), and respectively creates instructions to control various types of equipment constituting the indoor units (A1, A2) and the outdoor unit (B) by executing respective control programs. Thus, reduction in cost of the entire system is implemented while the system can be easily upgraded.