PROBLEM TO BE SOLVED: To provide a control device capable of suppressing dew condensation within a house and in crops.SOLUTION: A control device 2 controls the indoor environment inside the house in an agricultural house 1 for growing a crop 4. The control device 2 comprises: an arithmetic processing part 21 that determines whether it is necessary to suppress dew condensation inside the house using the humidity state of the indoor air of the house and the humidity state of the outside air； and an I/F part 20. The I/F part 20 controls at least one of a curtain 32, a skylight 30, a side window 31, and a dehumidifier so as not to raise the absolute humidity of the indoor air or not to lower the temperature of the indoor air, when it is determined that suppression of the dew condensation is necessary.SELECTED DRAWING: Figure 1
