In a spread illuminating apparatus comprising a light conductive plate, and at least one spot-like light source disposed close to a light entrance surface thereof, the light conductive plate has, on its light exit surface, a light scattering means comprising a plurality of mechanisms which are each formed so as to extend in a direction perpendicular to the light entrance surface, and which are adapted to scatter the light emitted from the at least one spot-like light source with respect to the direction parallel to the light entrance surface. The mechanisms of the light scattering means each consist of either paired slanting surfaces, a ridge with its surface arced in cross section, or a ridge multifaceted forming a polygonal cross section. The surfaces of the mechanisms may be roughened with a plurality of grooves, thereby achieving a further uniform illumination.