An illumination device (10, 20, 30, 50) comprising: a first lenticular lens sheet in which a plurality of first plano-convex cylindrical lenses which extend in a first direction are arranged in a direction perpendicular to the first direction; a second lenticular lens sheet in which a plurality of second plano-convex cylindrical lenses which extend in a second direction are arranged in a direction perpendicular to the second direction; and a third lenticular lens sheet in which a plurality of third plano-convex cylindrical lenses which extend in a third direction are arranged in a direction perpendicular to the third direction; characterised by at least one point light source that emits illumination light rays through the first to third lenticular lens sheets (11, 12, 13), wherein the second lenticular lens sheet is laminated on the first lenticular lens sheet such that an angle (θ1) formed by the first direction and the second direction falls within a first angle range having an upper limit of 30 degrees, the third lenticular lens sheet is laminated on the first and second lenticular lens sheets (11, 12) such that each of an angle (θ2) formed by the first direction and the third direction and an angle (θ3) formed by the second direction and the third direction falls within a second angle range, a lower limit of the second angle range is greater than an upper limit of the first angle range, the third lenticular lens sheet diffuses illumination light rays emitted from the point light source in a direction perpendicular to the third direction, the first and second lenticular lens sheets (11, 12) diffuse the illumination light rays in a direction substantially perpendicular to the first direction and the second direction, to generate a streaked illumination pattern along a diffusion direction substantially perpendicular to the first direction and the second direction, the first to third lenticular lens sheets (11, 12, 13) have circular shapes, and in a case where a diameter of the first to third lenticular lens sheets (11, 12, 13) is D and arrangement pitches of the first and second plano-convex cylindrical lenses are P, a lower limit of the first angle range is α min calculated by α min = atan(P/D). a first lenticular lens sheet in which a plurality of first plano-convex cylindrical lenses which extend in a first direction are arranged in a direction perpendicular to the first direction; a second lenticular lens sheet in which a plurality of second plano-convex cylindrical lenses which extend in a second direction are arranged in a direction perpendicular to the second direction; and a third lenticular lens sheet in which a plurality of third plano-convex cylindrical lenses which extend in a third direction are arranged in a direction perpendicular to the third direction; characterised by at least one point light source that emits illumination light rays through the first to third lenticular lens sheets (11, 12, 13), wherein the second lenticular lens sheet is laminated on the first lenticular lens sheet such that an angle (θ1) formed by the first direction and the second direction falls within a first angle range having an upper limit of 30 degrees, the third lenticular lens sheet is laminated on the first and second lenticular lens sheets (11, 12) such that each of an angle (θ2) formed by the first direction and the third direction and an angle (θ3) formed by the second direction and the third direction falls within a second angle range, a lower limit of the second angle range is greater than an upper limit of the first angle range, the third lenticular lens sheet diffuses illumination light rays emitted from the point light source in a direction perpendicular to the third direction, the first and second lenticular lens sheets (11, 12) diffuse the illumination light rays in a direction substantially perpendicular to the first direction and the second direction, to generate a streaked illumination pattern along a diffusion direction substantially perpendicular to the first direction and the second direction, the first to third lenticular lens sheets (11, 12, 13) have circular shapes, and in a case where a diameter of the first to third lenticular lens sheets (11, 12, 13) is D and arrangement pitches of the first and second plano-convex cylindrical lenses are P, a lower limit of the first angle range is α min calculated by α min = atan(P/D).