We have used scanning tunneling microscopy to obtain atomically resolved images of the lanthanum terminated LaB6(100) surface. The surface atoms are observed to occupy a square lattice with a La-La separation of 4 angstrom. A weak corrugation between La atoms is observed which is consistent with the delocalized metal-like nature of the states near the Fermi level. On a larger scale, the surface is composed of (100) terraces with an average width of 125 angstrom separated by steps one unit cell high. Approximately 10% of the La sites on the terraces are vacant.