We report for the first time about field emission from carbon-reconstructed phosphorus-doped homoepitaxial diamond surfaces. In order to achieve surface reconstruction, annealing at 950degC for 60 min in a high vacuum system has been applied. Field emission shows the lowest threshold field for the carbon reconstructed surface of 16 V/mum, while the threshold fields for oxidized and hydrogen-terminated surface are 28 V/mum and 44 V/mum, respectively. A model is introduced to discuss these results, which takes into account effective electron affinities and tunneling of electrons from the conduction band minimum and from the donor level