Epitaxial growth of iron phthalocyanine on a silver (111) surface has been studied with scanning tunneling microscopy in ultrahigh vacuum. Commensurate two-dimensional ordering with parallelogram unit vectors (b1, b2) where b1 = 5a1 + 2a2 and b2 = 5a2, where a1 and a2 are unit vectors of Ag(111) surface, were observed. The parallelogram structure was more commensurate than those of FePc on Au(111) or graphite and of CuPc on Ag(111), and the surface density is greatest on Ag(111). The orbital mediated tunneling spectra showed a first ionization potential at 5.1 eV, similar to that in cobalt phthalocyanine on Au(111) surface.