The present invention adjusts the discharge rate or discharge direction of air-conditioned air discharged from the discharge openings of air conditioners (301 to 308) according to the occupancy rates of work areas in the air-conditioned regions of the air conditioners (301 to 308). In this way, the work areas are intensively air-conditioned and the aisles and the space where cabinets and multifunctional machines are provided are moderately air-conditioned. Consequently, creating a comfortable environment around the users working in the work areas and reduce the energy consumption required for air-conditioning is possible.