A light emission device for simplifying a structure of an electron emission unit and a manufacturing process thereof is provided. A display device using the light emission device as a light source is also provided. The light emission device includes a vacuum panel having a first substrate and a second substrate facing each other. A sealing member is between the first and second substrates. Recesss portions each have a depth into a side of the first substrate facing the second substrate. Cathode electrodes are in corresponding recesses. Electron emission regions are on corresponding cathode electrodes. A gate electrode is fixed at one side of the first substrate at a distance from the electron emission regions. A light emission unit is at one side of the second substrate. The gate electrode includes a mesh unit having openings for passing through an electron beam and a supporting member surrounding the mesh unit.