A field-controlled composite insulator uses materials which are greatly stressed by an inhomogeneous distribution of an electrical field across a surface thereof. One of the causes thereof is the structural configuration of the insulator. The field strength changes particularly in a region of fittings due to a transition from insulating materials of sheds and an insulator core to a metal material, due to a transition from ground potential at cross members or to a conductor potential at that location, where conductor cables are attached. A further cause is deposits of dirt, which stress an insulator overall. A field control layer is therefore disposed between the core and the protective layer in at least one section of the insulator. The control layer includes particles as a filler, which influence the electrical field of the insulator. A method for producing the composite insulator is also provided.