To perform illumination at high projected angles by arranging light sources of many light emitting diodes on a cylinder and making parallel light ray fluxes proceed on grooves formed in a Frensnel type light scattering device having a smilar shape and making light ray fluxes proceed toward the surface of a product by being diffracted.

A housing 30 has 384 pieces of openings which are provided for, for example, 8 rings spaced each other in the axial direction of the housing and which are prolonged in the radial directing of the housing. LED lamps 32 in which ordinary light emitting diodes are assembled are provided in respective openings. Moreover, a circular. Fresnel type light scattering element 40 which is attached in the radial direction and the inner side with respect to the housing 30. Eight pieces of circumference shaped grooves spaced in the axial direction are formed on the outer circuimferentail surface of the element 40 and respective grooves form one pair of surfaces which cross with each other to deflect separate luminous fluxes to a common focus by diffracting light rays. Thus, light rays can be directed on a product W at high projected angles by combining the LED lamps 32 and the Frensnel type light scattering element 40.