The booth allows to obtain delimited environment area of clean and sterile air class ISO 5 (NF, EN, ISO 14644-1), through a unidirectional and descendant air filtered flow with lower pressure in the operation area. The possibility of cross contamination with other products is avoided. The downward air flow suppressing any powder cloud formation and then extracted to lower-level grills, enabling dust or vapors to be quickly carried away from the operator’s breathing zone. During circulation, a small amount (10-15%) of return air is exhausted out of booth, this keeps the booth under a slightly negative pressure than the room area, providing in- turn air flow back to booth. The room area(surroundings) is protected.