The present invention relates to a cross flow type cooling tower with which it is possible to prevent the emission of white vapor in cold weather with certainty. In order to accomplish the above object, the cooling tower of the present invention comprises: a heat dissipation unit having filling plates arranged vertically and parallel with each other so as to form dry air passages and moist air passages therebetween, each of the dry air passages and the moist air passages having inner surfaces; water supply means for supplying water to be cooled to the inner surfaces of the moist air passages for cooling the water by contact with air passing through the moist air passage; and water invasion stoppers provided at side ends of the filling plates for preventing the water flowing down the inner surfaces of the moist air passages from invading the dry air passages.