PROBLEM TO BE SOLVED: To provide a vacuum cooling device capable of shortening a time necessary for vacuum cooling.SOLUTION: In a vacuum cooling device including a processing tank 2 accommodating a cooled object, a vacuum generation device 1 sucking a gas in the processing tank, and a heat exchanger 4 for cooling the gas sucked from the processing tank, and cooling the cooled object by forming a vacuum inside of the processing tank, a drainage discharge passage is connected to the heat exchanger, and a low-temperature drainage storage portion 6, a high-temperature drainage cutoff valve 12, a high-temperature drainage storage portion 13, and a drain valve 11 are disposed in the drainage discharge passage successively from an upstream side. In implementing a vacuum cooling operation by the vacuum cooling device, the high-temperature drainage cutoff valve 12 is opened in a state of closing the drain valve 11 in an initial process of vacuum cooling, so that the drainage is stored in the high-temperature storage portion 13, and in a process of latter stage of the vacuum cooling implemented thereafter, the drainage generated in the heat exchanger is stored in the low-temperature drainage storage portion 6 at an upstream side of the high-temperature drainage cutoff valve by closing the high-temperature drainage cutoff valve 12.SELECTED DRAWING: Figure 1
