Abstract: A process for manufacturing a composite building panel of the type having a facing layer made from a plurality of facing elements, such as brick slices or stone slices, retained in a spaced apart relationship, and a magnetically attractable particulate material disposed between the facing elements to imitate mortar. In the process of making the building panel facing elements are placed in a holder having a plurality of recesses for receiving facing elements. Spacers are placed between said recesses for maintaining the facing elements in a spaced apart relationship. A magnetic field is generated in the vicinity of spacers for retaining thereto magnetically attractable particulate material. A backing layer is placed in a spaced apart relationship to the facing elements in the holder. A plastic material is then introduced between the facing elements and the backing layer for building an insulation layer.