Well-aligned beta-phase W(100) nanorods having square-base pyramidal apexes were grown on oxidized Si(100) substrate using glancing angle deposition technique with substrate rotation. The field emission characteristics of nanorods were measured using scanning tunneling microscope (STM) tip as an extraction anode. A highly confined emission current of about 23 muA was obtained at a low extraction voltage of similar to260 V at similar to280 nm anode-cathode distance with 3% fluctuations over similar to2 h. The Fowler-Nordheim plot of the field emission characteristics of nanorods is nonlinear compared with the linear behavior from a conventional W film. The STM topography after the field emission showed a type of nanolips structure grown over the pyramidal apex, which was suggested to enhance and stabilize the emission current. (C) 2004 American Vacuum Society.