An illumination device for a color sorter includes an LED substrate placed on a longitudinal chassis for heat radiation and a light source in which many LED elements are linearly aligned in the longitudinal direction on the LED substrate, and the light source is an integration of at least two light sources provided together, one of the light sources illuminating a side on which items-to-be-sorted flow down and the other one of the light sources illuminating a side of a background arranged to face a camera.