PROBLEM TO BE SOLVED: To provide an air-conditioning system capable of preventing an air contaminant such as dust from an ambient space and an operator from being caught on a patient side, and providing an optimum thermal environment to the operator and the patient.SOLUTION: A central blowout unit 11 is arranged above a patient area in an operation room 1, and a peripheral blowout unit 13 is arranged above an operator area adjacent to the periphery of the patient area respectively. Central blowout air 21 is blown out from the central blowout unit 11 to the patient area, and peripheral blowout air 23 is blown out from the peripheral blowout unit 13 to the operator area. The velocity of the central blowout air 21 is made greater than the velocity of the peripheral blowout air 23, and the temperature of the central blowout air 21 is made higher than the temperature of the peripheral blowout air 23.