Iron of high purity, in the form of 1-lb ingots, has been prepared by reducing purified iron oxide to sponge iron, melting the sponge iron, and remelting under hydrogen and in vacuo. The ingots were examined by spectroscopic and chemical methods for the presence of 55 possible impurities; the number of impurities that could be identified in individual ingots ranges from 6 to 9. The total of impurities in each ingot in most cases is less than 0.010 percent. The major impurities are nonmetallic, chiefly oxygen and sulfur, with traces of carbon, phosphorus, nitrogen, and hydrogen. Copper is the only metallic impurity in seven of the ingots; others contain small amounts of silicon and occasional traces of aluminum or beryllium from the refractories.