PROBLEM TO BE SOLVED: To suppress increase of relative humidity after switching from a light period to a dark period.SOLUTION: An air-conditioning system for cultivation chamber is an air-conditioning system for a cultivation chamber which performs air conditioning of a cultivation chamber (1) of plants where a light period and a dark period are alternately repeated, and the system has: an air conditioner (30) which has a refrigerant circuit for performing a refrigerating cycle, and controls the temperature in the cultivation chamber (1) to first temperature for the light period or second temperature for the dark period lower than the first temperature； and a control part (51) which controls preset temperature of the air conditioner (30). The control part (51) sets the preset temperature of the air conditioner (30) to the first temperature, and changes the preset temperature of the air conditioner (30) to the second temperature before a prescribed time of switching from the light period to the dark period.SELECTED DRAWING: Figure 3【課題】明期から暗期への切替後における相対湿度の上昇を抑える。【解決手段】栽培室用空調システムは、明期と暗期とが交互に繰り返される、植物の栽培室（1）内の空調を行う栽培室用空調システムであって、冷凍サイクルを行う冷媒回路を有し、上記栽培室（1）内の室温を上記明期用の第１温度又は上記第１温度より低い上記暗期用の第２温度に制御する空調機（30）と、上記空調機（30）の設定温度を制御する制御部（51）とを有する。上記制御部（51）は、上記空調機（30）の設定温度を上記第１温度に設定し、上記明期から上記暗期への切替の所定時間前に、上記空調機（30）の設定温度を上記第２温度に変更する。【選択図】図３
