To provide a water temperature adjusting type heat exchanger, capable of cooling water quickly and correctly to a set temperature when the water is sent thereinto and, further, low in a cost for the installation of the same.

The water temperature adjusting type heat exchanger, constituted so as to be capable of cooling high-temperature water, sent into the heat exchanger, to a predetermined set temperature by the heat exchanger, is characterized in a constitution, consisting of a plurality of sets of cooling mechanism bodies, connected to each other.