PROBLEM TO BE SOLVED: To provide a method by which appearance of deodorization mats or the like is kept clean without the need of frequently changing the deodorization mats or the like, and the generation of malodor is suppressed in various environments where the malodor is caused because a floor surface is wetted by urine or liquid that can generate putrid odor.SOLUTION: A lower mat 2 having a function of absorbing/holding urine or liquid that can generate the putrid odor and a moisture evaporating function together is spread on a floor surface, and an upper mat 3 is placed on the lower mat 2, wherein the upper mat is formed of a rigid material without water absorbability and includes a plurality of liquid permeable holes. A culture solution 4 to which facultatively aerobic microorganisms having a deodorization function and a sporulation function together are added is periodically or voluntarily sprayed to the lower mat 2. In order to control the water content of the lower mat 2 to be in the optimum range of the facultatively aerobic microorganisms having the deodorization function and the sporulation function together, the absorbing/holding function and the moisture evaporating function of the lower mat 2 and the spray amount of the cultivation solution are set according to the spilling amount on the lower mat 2 of the urine or the liquid that can generate the putrid odor in the above environments.
