GaAs(110) surfaces have been studied after etching in Br-2/H2O solutions and emersion from the electrolyte using high-resolution synchrotron-induced photoelectron spectroscopy. High-quality spectra of the core lines and the valence band region have been obtained by using a specifically developed transfer procedure, which allows synchrotron-induced XPS analysis after several transfers between the solution and vacuum. After treatment in Br-2/H2O solutions, the surface of GaAs is covered by a mixture of mostly Ga2O3, Ga(OH)(3), As2O3, and As2O5. After rinsing in liquid H2O, the arsenic oxides are dissolved leaving the GaAs surface covered with a layer of elementary arsenic and gallium oxides and hydroxides.