A fabricating method of an electron-emitting device is provided. The fabricating method of the electron-emitting device includes at least following procedures. Firstly, a substrate is provided. Next, a first electrode and a second electrode are formed on the substrate. Afterward, a conductive layer covering the first electrode and the second electrode is formed on the substrate. Then, a first conductive layer, a second conductive layer and a gap are formed by patterning the conductive layer. The gap is disposed between the first conductive layer and the second conductive layer. After that, a plasma process is performed at the first conductive layer and second conductive layer.