PROBLEM TO BE SOLVED: To provide a vacuum cooling device capable of quickly cooling by increasing a cooling speed.SOLUTION: A vacuum cooling device comprises: a processing tank 2 to store a processed material; a vacuum generation device 1 which is connected to the processing tank 2 through vacuum piping 5 and sucks gas in the processing tank; a heat exchanger 4 which condenses steam by cooling the gas sucked by the vacuum generation device 1; and a drain tank 6 to store drain generated in the heat exchanger 4. The vacuum cooling device cools the processed material stored in the processing tank by evacuating the gas from an interior thereof. The heat exchanger 4 and the drain tank 6 are connected to each other through a drain transfer pipe 7 and an air distribution pipe 8. A drain tank side edge of the drain transfer pipe 7 is installed at a position submerged in the drain accumulated in the drain tank 6. The air distribution pipe 8 is installed at the position not submerged in the drain. A ventilation valve 1
