The effects of low-energy (110 keV) nitrogen ion (N+) implantation at fluences of 1 × 1013 and 1 × 10 14 cm-2 in semi-insulating InP samples have been studied using cross sectional scanning tunneling microscopy. The atomically resolved images of the implanted samples reveal lattice disordering and point defects, which are attributed to implantation-induced effects. At fluence of 1 × 1014 cm-2, deformation of the atomic structures is observed. Cleaved-edge tunneling spectroscopy of the implanted samples has been carried out under dark conditions. The observed results demonstrate that two components of current are associated with the tunneling characteristics. Furthermore, the N+ implantation is observed to induce extended states in the conduction band in which the tunneling of electrons occur. Our results suggest that low-energy N+ implantation influences the atomic structures and the tunneling spectra of low-conductivity InP.