Using a complex of secondary and photoelectron spectroscopy methods, the effects of the implantation of In+ ions with an energy of E0 = 1 keV at different doses and subsequent annealing on the composition, electronic, and crystal structure of the GaP(111) surface were studied. It is shown that in the dose range D ≈ 5 × 1014–5 × 1015 cm−2 after annealing, nanocrystalline phases Ga0.6In0.4P are formed with surface dimensions d ≈ 10–30 nm, and at D ≥ 6 × 1016 cm−2 nanofilm–Ga0.6In0.4P with a thickness of 30–35 nm. It has been found that the band gap of nanophases (Eg ≈ 2–2.3 eV) is much larger than Eg of the film (~1.85 eV). For the first time, information was obtained on the density of state of electrons in the valence band of nanophases and nanofilm GaInP.