Solid/gas biocatalysis appears today as a promising technology for fundamental research and for the development of new cleaner industrial processes. The use of enzymes or whole cells at the solid/gas interface appears now concurrent to liquid processes and presents some very interesting features since total thermodynamic control of the system can be achieved easily. Moreover, on a technological point of view, solid/gas systems offer very high productivity for minimal plant sizes, allow important reduction of treated volumes and permit simplified downstream processes. These advantages result from the ability to control precisely all the thermodynamic parameters influencing not only the kinetics of the reactions performed, but also the stability of the biocatalysts working in a continuous way at temperatures far higher from the temperatures encountered in nature. In this article, an overview of some existing systems and application of solid/gas technology to fundamentals studies related to the influence of the microenvironment on biocatalyst is given. The potential of this peculiar system, and examples of applications that should get benefits of the technology are presented herein.