The influence of the defect, introduced into the diamond film by nitrogen doping, on an electron emission has been studied by electron spin resonance (ESR) method. It was observed that the nitrogen doping (N/C = 1-10) introduced the paramagnetic defects into the N-doped diamond film. The conductivity of the diamond film was increased with the increase in the N/C ratio, because of the variable range hopping of carriers through the defect-induced energy band(s). The current density of the electron emission was increased up to 250 muA cm(-2) along with an increase in the defect density and the conductivity of the diamond film.