Prefabricated stable floor element comprising a supporting element (2) made of concrete, with a service face (6) situated at the top when in use and a bottom face (7) situated on the bottom side, whereby the service face (6) has one or several recesses or openings (5), characterised in that in at least one of these recesses or openings (5) has been provided an insert element (9) made of rubber or an elastic synthetic material, which insert element (9) reaches as of the inner space in the recess or the opening (5) in which it has been provided in order to fix the insert element (9), to right underneath, in line with or above the service face (6), i.e. seen in the position of use of the stable floor element (1).