A microscope illumination device includes a white LED light source, and an illumination optical system that includes an aperture stop on a plane on which light from the white LED light source is condensed. The white LED light source includes a board, a plurality of LED chips that are arranged on the board and that each emit excitation light, and a phosphor layer that is provided so as to cover the plurality of LED chips and that includes at least three types of phosphors. The plurality of LED chips are arranged so as to be projected into an aperture of the aperture stop.