PURPOSE: To provide a cooling tower which performs operation responding to a cooling water temperature.

CONSTITUTION: In a cooling tower 10, a fan motor 13 is arranged to the inner upper part of a casing 11, a fan 14 is run with the aid of the fan motor 13, cooling water is cooled by dripping cooling water from a sprinkler 15 in the casing 11 to a filler unit 16, and cooling water after cooling can be stored in a water tank 12. The temperature of cooling water fed to a freezer 20 is detected by a cooling water temperature sensor 51, and fed to a control device 53 of an operation control device 50. In a control device 53, during the starting of the fan motor 13, a frequency signal changed at intervals of a given time is outputted until a frequency attains a set value determined by a cooling water temperature detected by the cooling water temperature sensor 51. A frequency signal from the control device 53 is fed to an inverter device 55. The inverter device 55 rotationally drives the fan motor 13 according to the frequency signal therefrom. This constitution and method regulate an airflow of the cooling tower 10 and regulate cooling capacity.