Cast iron is important engineering material such as for machines and automotive industry parts. Cast iron is often manufactured in electric induction furnaces. There are various types of cast irons such as grey cast iron, ductile cast iron and Ni-resist cast iron. Specific property of each cast iron is controlled by the concentrations of alloying elements. Therefore, the rapid elemental analysis of the alloying elements including carbon and silicon for controlling composition of molten metal in furnaces is crucial for the quality control in the cast iron production. Sand casting molds are mostly used for casting cast iron. The elemental analysis of casting sands such as silica sand and olivine sand is also required to check the quality of recycled casting sands. The X-ray fluorescence spectrometer ZSX PrimusIII+ can cover all necessary elemental analyses from carbon for various kinds of cast iron and casting sand. This note describes the application of cast iron analysis including ductile cast iron.