To provide a cooling tower which obtain an uniform cooling characteristic and a higher cooling efficiency and moreover, enables adaptation to changes in a heat load, by preventing a drop in a local cooling efficiency as caused by the unevenness of the intake of outside air and an operation method thereof and a recording medium with a cooling tower operation procedure recorded.

This cooling tower 1 is provided with a blower 80, a heat exchanger 5 through which a fluid W to be cooled is passed, a water sprinkling part 7 for sprinkling water on the outer surface of the heat exchanger 5, and louvers 41-4K arranged on the perimeter of the heat exchanger 5. Outside air SF sucked by the blower via the louvers 41-4K makes water 8 sprinkled on the outer surface of the heat exchanger 5 evaporate to cool the fluid W to be cooled. An angle θ1 of inclination applied horizontally is set larger for the louver 41 mounted at a position closer to the blower 80, and an angle θK of inclination is smaller for the louver 4K far from the blower 80.