Abstract: The invention relates to wall elements and preferably to such elements intended for use in the construction of office landscapes, bookshelves and the like. Wall elements intended for this purpose are provided with a stiffening frame structure to which is applied a casing forming the outer surface of the wall element. The fastening means intended for the wall element are securely connected to the reinforcing frame and arranged to extend from the frame through a distance such that the free end of the fastening means is at least located in a plane with the casing and preferably extends slightly beyond said casing.The present invention also relates to an element fastening device, where the element has one or more retaining means in the form of a peg provided with a narrow web portion located at a distance from the free end of the peg.