Abstract: The present device is a locking mechanism for a piece of seating furniture that is continuously foldable, comprising a cylindrical bushing (3), which is fixed to the frame of the piece of seating furniture and which is provided with a pair of diagonally arranged holes (4) for an upwards inclined carrier bar (6), which is fixed to the seat part, and comprising a locking member (7) jointly operative with the carrier bar (6) as well as a control member (8) acting upon the locking member (7).