The authors report a monolithically fabricated triode for microplasma generation at atmospheric pressure. The microstructure is fabricated using a self-aligned electroplating process and a stable glow discharge is generated at atmospheric pressure. The generated plasma can be expanded by applying a lateral electric field using an integrated secondary cathode. I-V characteristics of the microtriode were measured in the glow discharge mode and indicated significant amounts of the ionized gas atoms were drifted to the secondary cathode, demonstrating its ability to enlarge the volume of the plasma. (c) 2007 American Vacuum Society.