A diffuser plate of a microlens array type, the diffuser plate comprising: a single lens group located on a surface of a transparent base material, wherein aperture sizes and radii of curvatures of respective single lenses constituting the single lens group vary in the single lens group as a whole, and vertex positions of the respective single lenses are located irregularly, and energy distribution of light that transmits through the single lens group is substantially even in a predetermined diffusion angle range, wherein the expression 0.015 ≤ ΔZ max Z ≤ 0.086 is satisfied, where a maximum elevation difference in the vertex positions between the single lenses constituting the single lens group is represented by ΔZ max, and a maximum vertex height in the single lens group is represented by Z, and wherein the vertex positions of the respective single lenses constituting the single lens group are located irregularly using positions of vertices of the respective single lenses when assuming that the single lenses are arranged regularly as a reference, such that a moved amount from the reference falls within a predetermined range, and the expression M 2 × 2 φ 2 + R 2 ≥ 0.12 is satisfied, where the moved amount at maximum in the single lens group is represented by M, a reference aperture size of the single lens group is represented by φ, and a reference radius of curvature of the single lens group is represented by R, and wherein the respective single lenses constituting the single lens group are located irregularly on the transparent base material, and the expression O ν φ 2 + R 2 ≥ 0.12 is satisfied, where a maximum value of an overlying width between the single lenses adjacent to each other in the single lens group is represented by O v, a reference aperture size of the single lens group is represented by φ, and a reference radius of curvature of the single lens group is represented by R. a single lens group located on a surface of a transparent base material, wherein aperture sizes and radii of curvatures of respective single lenses constituting the single lens group vary in the single lens group as a whole, and vertex positions of the respective single lenses are located irregularly, and energy distribution of light that transmits through the single lens group is substantially even in a predetermined diffusion angle range, wherein the expression 0.015 ≤ ΔZ max Z ≤ 0.086 is satisfied, where a maximum elevation difference in the vertex positions between the single lenses constituting the single lens group is represented by ΔZ max, and a maximum vertex height in the single lens group is represented by Z, and wherein the vertex positions of the respective single lenses constituting the single lens group are located irregularly using positions of vertices of the respective single lenses when assuming that the single lenses are arranged regularly as a reference, such that a moved amount from the reference falls within a predetermined range, and the expression M 2 × 2 φ 2 + R 2 ≥ 0.12 is satisfied, where the moved amount at maximum in the single lens group is represented by M, a reference aperture size of the single lens group is represented by φ, and a reference radius of curvature of the single lens group is represented by R, and wherein the respective single lenses constituting the single lens group are located irregularly on the transparent base material, and the expression O ν φ 2 + R 2 ≥ 0.12 is satisfied, where a maximum value of an overlying width between the single lenses adjacent to each other in the single lens group is represented by O v, a reference aperture size of the single lens group is represented by φ, and a reference radius of curvature of the single lens group is represented by R.