Abstract: An electron beam apparatus for patterned metal reduction, applied to generate metal lines or patterns on a substrate, includes an electron beam generating system with functions of collimating, focusing and scanning electron beams, an electron-transparent membrane of a vacuum chamber for allowing the electron beam to penetrate through, a stage mounted at a position to face the electron-transparent membrane, a substrate placed on the stage to face the electron-transparent membrane, a thin liquid layer containing metal ions and mounted on the substrate, and an environment control device for controlling the temperature, the pressure and the atmosphere around the substrate. A method for using the electron beam apparatus to generate the metal lines or patterns on the substrate is to focus the electron beam onto the substrate and have the electron beam to scan the substrate repeatedly along a predetermined path till a desired metal pattern is reduced on the substrate.