A plane illumination apparatus comprising: an optical device configured to be capable of diffusing coherent light beams incident on respective points on the optical device to an entire region of corresponding areas in an illumination zone; an irradiation unit configured to irradiate coherent light beams to the optical device so that the coherent light beams scan a surface of the optical device; and a light guide plate configured to make coherent light beams that are reflected at a surface of the optical device or that have passed through the optical device propagate within the light guide plate and to take out the coherent light beams to the outside, wherein the irradiation unit makes the coherent light beams scan the surface of the optical device by changing propagation directions of the coherent light beams, the light guide plate comprises a light take-out portion configured to take out coherent light beams to the outside while making coherent light beams propagate between a first end face on which coherent light beams from the optical device are incident and a second end face that is provided to face the first end face, the illumination zone is provided within the light take-out portion or along the first end face, or along the second end face, characterised in that the optical device comprises a hologram recording medium with a plurality of recording areas (r1 to rn) provided thereon that are scanned by coherent light beams having propagation directions changed within different angle ranges by the irradiation unit, the illumination zone comprises a plurality of image reproduction areas (LZ1 to LZn) corresponding to the plurality of recording areas (r1 to rn), respectively, the plurality of recording areas (r1 to rn) correspond to the plurality of image reproduction areas (LZ1 to LZn), respectively, and an interference fringe is recorded in each of the plurality of recording areas (r1 to rn), to reproduce an image of a scattering plate on the entire region in the corresponding image reproduction area (LZ1 to LZn). an optical device configured to be capable of diffusing coherent light beams incident on respective points on the optical device to an entire region of corresponding areas in an illumination zone; an irradiation unit configured to irradiate coherent light beams to the optical device so that the coherent light beams scan a surface of the optical device; and a light guide plate configured to make coherent light beams that are reflected at a surface of the optical device or that have passed through the optical device propagate within the light guide plate and to take out the coherent light beams to the outside, wherein the irradiation unit makes the coherent light beams scan the surface of the optical device by changing propagation directions of the coherent light beams, the light guide plate comprises a light take-out portion configured to take out coherent light beams to the outside while making coherent light beams propagate between a first end face on which coherent light beams from the optical device are incident and a second end face that is provided to face the first end face, the illumination zone is provided within the light take-out portion or along the first end face, or along the second end face, characterised in that the optical device comprises a hologram recording medium with a plurality of recording areas (r1 to rn) provided thereon that are scanned by coherent light beams having propagation directions changed within different angle ranges by the irradiation unit, the illumination zone comprises a plurality of image reproduction areas (LZ1 to LZn) corresponding to the plurality of recording areas (r1 to rn), respectively, the plurality of recording areas (r1 to rn) correspond to the plurality of image reproduction areas (LZ1 to LZn), respectively, and an interference fringe is recorded in each of the plurality of recording areas (r1 to rn), to reproduce an image of a scattering plate on the entire region in the corresponding image reproduction area (LZ1 to LZn).