Abstract: A method for performing a function or an operation involving a material, in particular, a non-gaseous material such as a biological material subjected to a scientific investigation, under a gaseous atmosphere in a closed chamber comprising performing the operation in a housing comprising i) first chamber walls defining a first chamber containing a gaseous atmosphere and ii) second chamber walls defining a second chamber substantially enclosing the first chamber, the second chamber containing a gaseous atmosphere between the first and second chamber walls, the operation being performed in the first chamber while a) the partial pressure of the selected gas species or the total gas pressure in the atmosphere of the second chamber is lower than the partial pressure of the selected species of the total gas pressure, respectively, of the gaseous atmosphere in an adjacent outer third chamber or space. The invention also relates to a housing for performing the operation mentioned above.