A miniature Schottky electron source has been developed and evaluated for applications in a new generation of scanning tunneling microscope aligned field emission microcolumns. Both the physical dimensions and the heating power of this source have been significantly reduced from a conventional source of the same kind. Operating parameters for such a source in a microcolumn environment in terms of emission characteristics, suppressor operating range, etc., have been evaluated. Test results show that very good emission stability at greater than or equal to 100 mu A emission current over several hours, and axial angular current densities in excess of 100 mu A/sr can be obtained. Energy distributions have been measured using a carefully calibrated analyzer, and the results show a full width at half-maximum of 0.4 to 0.76 eV for a 0.3 mu m radius Schottky source operating over an angular current density range of 1 to over 100 mu A/sr. A significant change in the shape of the energy distribution was observed over this range of operation, indicating evidence of tunneling currents at the high angular current density regime.