Abstract: A construction element for constructing a supporting floor or the like consists of a slab made of reinforced concrete. The side walls of the slab are provided with protection profiles connected with each other. Two series of aligned, alternating projections and complementary recesses are lying above each other on each side wall of the slab, wherein the projections of one of the series are staggered with respect to the projections of the other series in such a manner that the recesses of one of the series lie above respectively below the projections of the other series. The projections of the lower series lie at a distance from the lower surface of the slab. As the construction elements forming a supporting floor are connected with each other by the interlocking projections and recesses of the adjacent side walls, the load of a construction element is distributed over the adjacent construction elements so that each construction element can take up a very high load.