PURPOSE: To permit to effect both of dry type operation as well as wet and dry type operation by a method wherein a plurality of water cooling tower cells are arranged to make the cooling tower in which wet type cooling sections are opposed and dry type cooling section is provided in the cell.

CONSTITUTION: Wet type cooling sections 1, effecting direct heat exchange between atmosphere and hot-water to be treated, are arranged so that the cooling tower cells 2, opposing to the wet type cooling sections 1, are arranged in parallel while partitioning plates 3 are provided between the cells 2. Communicating ports 4 are provided on the partitioning plates so as to be closed to the side of both wet type cooling sections 1 and the dry type cooling sections 5, consisting of finned tubes, are provided in he communicating ports 4. The communicating port 4 is provided with an opening and closing door 6 at the side opposing to the dry type cooling section 5 and the tip end 6a thereof closes the communicating port 4 when closed and is abutted against a bulkhead 7 provided in the wet type cooling section 1 when opened, thus, dry and wet type path 8 is formed in the wet type cooling section 1a. The wet type cooling section 1b, exclusively used for the wet type, is formed at the other side of the bulkhead 7. Openable and closable louvers 10a, introducing the atmosphere into the dry type cooling sections 5, are provided on the side plates of the cells at both right and left ends of the cells 2 provided in parallel.