Microcosms approach is an increasingly used technique at laboratory scale as a way to acquire the most important information on biodegradation. This depends on several factors mainly the easy handling of microcosms and the facility to have a lot of data in comparison with in field tests. Notwithstanding the use of this experimental approach, the microcosm methods are not standardised at all and the obtained data are mainly at the only use of the researchers; in fact, in several cases of applications in field, the biodegradation patterned differently. In the present paper an attempt to standardise a homogeneous soil microcosm, with the purpose to allow to perform biodegradation test with fungi on volatile chemicals, is described and candidated. The microcosm set-up, the fungal inoculum procedure as well as the sampling and the statistical treatment of analytical data are described and commented.