To provide an energy-saving air-conditioning system that can sufficiently reduce temperature around a plant during air-conditioning operation.SOLUTION: An air-conditioning system has an air conditioning unit (30) that has an air inlet (35) and an air outlet (41) and performs air-conditioning operation and heating operation in a switching manner. Both of the air inlet (35) and air outlet (41) are positioned below a plant (P) cultivated in a cultivation chamber (11).SELECTED DRAWING: Figure 2【課題】冷房時において、植物の周囲の温度を十分に低減できる省エネルギーな空調システムを提供する。【解決手段】空調システムは、吸込口(35)及び吹出口(41)を有し、冷房運転及び暖房運転を切り換えて行う空調ユニット(30)を備える。吸込口(35)及び吹出口(41)の双方が、栽培室(11)で栽培される植物(P)よりも低い位置に配置される。【選択図】図2