Apparatus for packaging a pourable product, comprising: - a first housing delimiting therein an isolation chamber configured to contain an atmosphere controlled in a sterile and/or aseptic condition; - a filling machine for filling containers with said pourable product, said machine being housed in the isolation chamber ; and - a fluidic circuit comprising a main conduit or duct configured to feed a working fluid into the isolation chamber ; wherein the apparatus further comprises a second housing delimiting therein a test chamber , said test chamber being operatively separated from the isolation chamber and configured to contain an atmosphere controlled in sterile and/or aseptic condition; wherein the isolation chamber is external with respect to the test chamber ; and wherein the fluidic circuit comprises a branch extending from the main duct to the test chamber for conveying the working fluid therein and allowing a sampling of the working fluid inside the test chamber ; wherein the isolation chamber defines a sterile and/or aseptic production area (P), the filling machine being arranged in the production area (P); wherein the test chamber defines a test area (T) for the working fluid, said test area (T) being sterile and/or aseptic and operatively separated from the production area (P), the production area (P) being external to the test area (T); and wherein the branch is configured to convey the working fluid to the test area (T), for allowing a sampling of the working fluid inside the test area (T) and externally relative to the production area (P); characterized in that the branch comprises a terminal arranged in the test area (T) and configured to receive in coupling a test device , for the sampling of the working fluid inside the test area (T) and externally relative to the production area (P). - a first housing delimiting therein an isolation chamber configured to contain an atmosphere controlled in a sterile and/or aseptic condition; - a filling machine for filling containers with said pourable product, said machine being housed in the isolation chamber ; and - a fluidic circuit comprising a main conduit or duct configured to feed a working fluid into the isolation chamber ; wherein the apparatus further comprises a second housing delimiting therein a test chamber , said test chamber being operatively separated from the isolation chamber and configured to contain an atmosphere controlled in sterile and/or aseptic condition; wherein the isolation chamber is external with respect to the test chamber ; and wherein the fluidic circuit comprises a branch extending from the main duct to the test chamber for conveying the working fluid therein and allowing a sampling of the working fluid inside the test chamber ; wherein the isolation chamber defines a sterile and/or aseptic production area (P), the filling machine being arranged in the production area (P); wherein the test chamber defines a test area (T) for the working fluid, said test area (T) being sterile and/or aseptic and operatively separated from the production area (P), the production area (P) being external to the test area (T); and wherein the branch is configured to convey the working fluid to the test area (T), for allowing a sampling of the working fluid inside the test area (T) and externally relative to the production area (P); characterized in that the branch comprises a terminal arranged in the test area (T) and configured to receive in coupling a test device , for the sampling of the working fluid inside the test area (T) and externally relative to the production area (P). <EOS>