PURPOSE: To provide an open type or closed type cross flow type cooling tower capable of eliminating disadvantages of a cross-flow type and a counter-flow type cooling towers and of having only the advantages.

CONSTITUTION: An open type cooling tower is comprised of an upper water tank 2 for storing cooling water, a heat exchanger arranged below the upper water tank 2 and a forced fan 5 arranged below the heat exchanger 3 and for supplying cooling air to the heat exchanger 3. The cooling water is cooled at the heat exchanger 3 with cooling air supplied from a forced fan 5. Then, there is provided a flow passage structure in which the cooling air from the forced fan 5 is passed through the heat exchanger 3 in a lateral direction.