The present invention provides a light emission device and a display device with the light emission device as the light source. The light emission device includes first and second substrates facing each other, electron emission elements on the first substrate, a light emission unit with an anode electrode and a phosphor layer on the second substrate, and spacers between the first and second substrates. Each spacer includes a spacer body comprising a dielectric material, a first coating layer on a first region of the spacer body, the first region being adjacent to the first substrate, and a second coating layer on a second region of the spacer body, the second region being adjacent to the second substrate, wherein a maximum secondary electron emission coefficient of the first coating layer under an operation voltage condition applied to the first region is about 0.8 to about 1 and a maximum secondary electron emission coefficient of the second coating layer under an operation voltage condition applied to the first and second regions is about 3 to about 16.