An electron emission device includes a cathode device and a gate electrode. The gate electrode is separated and insulted from the cathode device. The gate electrode includes a carbon nanotube layer having a plurality of spaces. A display device includes a cathode device, an anode device spaced from the cathode electrode and a gate electrode. The gate electrode is disposed between the cathode device and the anode device. The cathode device, the anode device and the gate electrode are separated and insulted from each other. The gate electrode comprises a carbon nanotube layer having a plurality of spaces.