PURPOSE: To improve heat exchanger efficiency in an evaporative heat exchanger used for space and the like by disposing a first heat exchanger part provided with a cooling medium flow passage and a cooled medium flow passage adjoiningly at the periphery of an approximately cylindrical second heat exchanger part.

CONSTITUTION: This evaporative heat exchanger 1 is formed of a first and a second heat exchanger parts 3, 5, and the first heat exchanger part 3 is formed by providing a cooled medium passage 9 in which a cooled medium (a) flows along the periphery of a first cooling medium passage 7 in which a first cooling medium bb flows, interposing a bulkhead 11. The second heat exchanger part 5 is disposed inside the first heat exchanger part 3 and provided with a cooled medium passage 23 in which the cooled medium (a) flows along the periphery of a cylindrical container 21 as well as a spray nozzle 25 for spraying a second cooling medium (b) above the container 21. The container 21 and the passage 23 are partitioned by a cylinder bulkhead 27. The first cooling medium passage 7 is formed of plural passages approximately in the spiral form, and press the first cooling medium bb to the bulkhead 11 by the centrifugal action.