The study of field electron energy spectra from amorphous carbon-nitride (a-CN) films is essential to understand the mechanism of field emission from this promising material. In this work, the electron energy spectrum is studied by measuring the distribution of electron field emitted from individual emitting sites. The spectra are recorded at different electrical fields. It is found that the peak shift as well as the half-width increase with increasing applied fields. Furthermore, multi-peak features are observed at the low-energy side of the spectra. It is assumed that these peaks might originate from the interband states of a-CN film. We propose that although the emission mainly originates from current injection into conduction band of a-CN film, the electrons may also be emitted from interband states.