PURPOSE: To carry out an examination of judging properly mildewproofing effects in a humid environment with much sweating, by doing a prliminary examination with specific fed strains to give test specimens which are found to have mildewproofing effect, and subjecting them to practical examination with given fex strains.

CONSTITUTION: Aspergillus negar, etc., are used as strains for preliminary examination, and suspensions (A) of their spores are formed. On the other hand, test pieces (B) having absorbed test specimens (e.g., mildewproofing coating compounds) are obtained. A medium for examination is prepared, the component B is stuck to the medium, the component A is applied to the component B, and cultivated. Consequently, strains having mildewproofing effect are used for practical examination. Alternaria altenata, etc. are used as strains for the practical examination, suspension (C) of mixed spores of these organisms is prepared. It is applied to another test specimens, cultivated, produced molds are removed to give pretreated test specimens (D). The test specimens having effects in the preliminary examination are applied to the component D, the component C is applied to the whole faces of the test specimens, the microorganisms are cultivated at 23W30°C at 90W100% relative humidity for 6 months, to judge mildewproofing effect.