A cooling device that can maintain or improve a cooling ability without being affected by fluctuation in an ambient temperature. Gas is supplied to a cooling target to cool the cooling target. A cooling device includes a cooling gas including gas having thermal conductivity higher than the thermal conductivity of the air, a partition wall that closes and stores the cooling target and the cooling gas and is capable of circulating the cooling gas, a cooling section that cools and circulates the cooling gas, a pressure determining section that determines the pressure of the cooling gas, and a cooling control section that controls the cooling section. The cooling control section causes the cooling section to change the pressure of the cooling gas and/or change the circulation speed of the cooling gas on the basis of a result of the determination of the pressure determining section.