Abstract: The present invention concerns a clean room featuring a closed enclosure having at least two opposite walls, a first of said walls being provided with blower means adapted to blow into said room a gaseous fluid, in particular air, having a specified controlled particle concentration, and a second wall being provided with evacuation means adapted to evacuate the gaseous fluid blown into said room. In accordance with the invention, said first wall is divided into at least two blower sectors, the blower means of each of said blower sectors blowing a gaseous fluid that has a uniform particle concentration different from the particle concentration of the other blower sector.