Provided is a surface light emitter that supplies light using a light guide method, and ensures transparency by lowering a haze value in a thickness direction at the time when a light source is turned off, and enables highly efficient light emission by using plate-surface transversal radiant emitted light at the time when the light source is on. A surface light emitter (2) including light diffusing particles guides light in a length direction of the light guide while scattering the light in the thickness direction of the light guide while scattering the light in the thickness direction of the light guide, and a calculated value (m−1/%) obtained by dividing a luminance attenuation coefficient E (m−1) by a haze value (%) per 5 (mm) thickness of the light guide is greater than or equal to 0.55 (m−1/%) and less than or equal to 10.0 (m−1/%).