A method and an apparatus of evaporative cooling for reducing the volume of an evaporative cooler by considerably lowering the temperature of a cooling fluid are disclosed. A first cooling fluid, which comprises most part of the cooling fluid evaporatively cooled by an outside air while passing through an evaporative cooling section after circulating in an apparatus to be cooled, re-circulates in the apparatus to be cooled. A second cooling fluid, which is separated from the cooling fluid after being cooled in the evaporative cooling section, passes through a sensible air-cooling section placed at an outside air inlet. Thereby, the inflow outside air is sensibly cooled. The second cooling fluid, which passes through the sensible cooling section, re-circulates in the evaporative cooling section.