Provided is a cooling device with which it is possible to cool a fluid to be cooled, even before maintenance work, if a fault such as a blockage or a breakage occurs in a part of a channel. The cooling device (1) is provided with four heat exchangers (1A-1D) and a plurality of heat exchanger connection parts (111-120), each of the heat exchanger connection parts allowing natural gas to flow therethrough. Each of the heat exchangers has: a drum (101, 102, 103, fourth drum 104), a refrigerant reservoir (T), a plurality of heat exchanger core parts (121, 122, 123, 124) immersed in liquid propane in the refrigerant reservoir (T), and a demister (106). A plurality of cooling channels allowing natural gas to flow therethrough are installed, independent of each other, from the first heat exchanger (1A) to the fourth heat exchanger (1D).