We have measured energy spectra of field emission (FE) electrons from multiwalled carbon nanotubes in various conditions such as a tip temperature, electric fields, the emission direction, and adsorption. The observed spectra indicated that peak near E-F originated from the FE electrons from the inner walls, while FE electrons forming the shoulder at deeper energy came from a surface wall. Both the position and the intensity of the shoulder changed from one specimen to the others; no spectra were the same as the others. The Fermi level of the surface wall is different from that of the inner walls under the FE condition. (C) 2003 American Vacuum Society.