A lighting unit, includes: a light source section wherein a plurality of light-emitting sources are arranged in a direction perpendicular to a direction of each light-emitting optical axis of each light-emitting source and linearly at predetermined intervals; and a reflecting section which reflects light emitted toward a direction along a document mounting surface from the light source section arranged along the document mounting surface toward an irradiated region of the document mounting surface, the reflecting section having: a first reflecting surface disposed closer to the light source section than to the irradiated region; and a second reflecting surface disposed more distant from the light source section than from the irradiated region.