The present work is devoted to investigation of field emission features of carbon nanotubes produced directly on the arc cathode during arc discharge vaporization of graphite under conditions favorable for fullerene synthesis. Field emission microscopy and scanning electron microscopy were both employed in studies of the structure of the emitting surface. Field emission characteristics measured over an emission current range of four to five orders of magnitude closely follow linear dependencies in the Fowler-Nordheim coordinates. Direct observations of the emitting surface in a field emission microscope have revealed high density and uniformity of emission centers and very low operating voltages. Based on the electron microscopic data, it was shown that the anomalously low threshold for field emission cannot be explained from the geometrical factor. (C) 2003 Published by Elsevier Science B.V.