To achieve an effective cooling operation in a refrigerating machine cooling system in which a heat generating part and a high temperature part of a refrigerating machine are contained in a closed casing.

In the refrigerating machine cooling system, the compressor 22 and the heat generating part 24 of the refrigerating machine 20 are contained in the closed casing 10. A boiling part 28 of a boiling type cooler is made to come into contact with the heat generating part 24 in the casing. A condensing part 40 and heat radiating fins 42 are disposed outside the casing. The boiling part is connected to the condensing part by connection piping 30 so as to circulate a refrigerant. In the refrigerating machine cooling system, since a cooling efficiency is not deteriorated even when the piping is bent, a space in the casing can be effectively used to increase the degree of freedom in the arrangement of components. Since outside air is not introduced to the casing because of cooling, raindrops do not enter and the corrosion prevention treatment of the components is not required.