order to enable as complete a permeation as possible the hard material bodies 7 exhibit an open porosity the hard material bodies 7 consist of a foam ceramic with high temperature stability which retains its open pored structure during the casting process i e at the casting temperature of the metal molten mass in the example embodiment the hard material bodies 7 are formed by a foam ceramic such as are known from casting filters for iron base alloys preferably casting iron the pore density of the hard material bodies 7 measured in ppi pores per square inch is chosen according to the casting material a foam ceramic which can be used as a filter for the molten mass in question naturally already exhibits a porosity which is favorable for as complete a permeation as possible such that adapting essentially poses no problems since greater demands are made on the casting filter with regard to through flow and therefore permeability because of the greater danger of occlusion in filter applications this demand for complete permeability is easily fulfilled when using casting filter materials since for producing the metal casting molded body 1 material has to flow through the hard material bodies 7 i e permeate them only once it can be assumed that all casting filters which are used for filtering iron base molten masses are also suitable as hard material for the compound material of the metal casting molded body 1 it can be assumed that the pore density of the hard material bodies 7 can even be greater for the metal casting molded body 1 than the pore densities of conventional casting filters for iron base molten masses the casting matrix 4 is formed for example from.