Workspace dividing partition resting via a lower edge on the top face of a wall forming a work surface and incorporating a device for attaching the partition to the work surface. The partition includes placement means comprising a translationary mobile branch which with the lower edge of the partition forms a clamp type mechanism situated on either side of an external overhang of the work surface, wherein the branch is able to move between a position in which it presses with contact against the underside of the work surface in order to attach the partition, and a position distant from the underside in order to release the partition. The partition also includes placement control means, situated near the overhang and reproducing, in a direction appearing parallel to the work surface, the movement and positioning of the mobile branch with respect to the work surface.