In order to provide an inspection illumination device that makes it possible to greatly change a light amount within an observation solid angle of an imaging device even in a case where a change in reflection or scattering taking place at a feature point is subtle, and thus detect such a minute feature point, the inspection illumination device includes: a surface light source that emits inspection light; a lens that is arranged between the surface light source and an inspection object, and provides an image of the surface light source near the inspection object; and a first light shielding mask that is arranged between the surface light source and the inspection object, and forms a dark domain within an illumination solid angle of the inspection light applied to each point on the inspection object.