Abstract: The partition wall comprises a lower horizontal rail provided with a tongue, rectangular panels each having on two adjacent sides tongues and on the opposite sides grooves, the panels being fitted together and mounted on the lower rail. The panels are disposed in superimposed rows in laterally staggered relation. A horizontal upper rail is fitted on the upper row of panels. Clamping devices are carried by the upper rail and bear against a ceiling and thereby press the panels against each other.