PROBLEM TO BE SOLVED: To activate photosynthesis of plants immediately after switching from a dark period to a light 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 second temperature, and changes the preset temperature of the air conditioner (30) to the first temperature before a first prescribed time of switching from the dark period to the light period.SELECTED DRAWING: Figure 3
