A novel high-fidelity pattern transfer and microfabrication method using a scanning micro-/ nanonozzle is presented. Reactive species created in a downstream plasma source are transported through a capillary which is pulled to form a nozzle. Due to the high directionality of the emerging particle beam, a strongly localized etching or deposition is induced. By scanning the sample a small distance under the nozzle a pattern transfer is performed. Fundamental principles of this technology, such as transport of free radicals through high aspect ratio capillaries, localized etching, and high etching rates without ion bombardment, are demonstrated in this work. The achieved etching rates are up to 1.1 mu m per minute in silicon. Combining the microplasma source with scanning probe techniques provides an instrument for simultaneous in situ structuring and imaging.