We report the first simultaneous measurements of the photoluminescence yield and of the basic electronic properties (density of states, position of the Fermi level) of InP surfaces subjected to various treatments under ultrahigh vacuum conditions. The surface densities of states located near the band edges are found to govern the surface recombination process. Annealing under As pressure which moves these densities out of the band gap is shown to yield a surface with low surface recombination, in agreeement with this framework.