A field emission device, a field emission display device, and a method for manufacturing the same are disclosed. The field emission device includes: i) a substrate; ii) an electrode positioned on the substrate; iii) a mask layer positioned on the electrode and including one or more openings; and iv) a plurality of nanostructures positioned on the electrode via the openings and formed to extend radially. The plurality of nanostructures may be applied to emit an electron upon receiving a voltage from the electrode.