Empty and filled surface states have been measured for gallium- and phosphorus-rich GaP(1̄1̄1̄)P surfaces using electron energy loss spectroscopy at 100 eV and photoemission at 4.5 ⩽ ħω ⩽ 6.6 eV. The surfaces are prepared by molecular beam epitaxy and analysed by Auger electron spectroscopy. The empty surface states are connected with the gallium-rich surface and the filled surface states with the phosphorus-rich surface. A lateral long range order of the surface atoms is not necessary for the appearance of these surface states.