An optical body includes a first optical layer having a concave-convex surface, a wavelength-selective reflecting layer formed on the concave-convex surface, and a second optical layer formed on the wavelength-selective reflecting layer to embed the concave-convex surface, the wavelength-selective reflecting layer having a multilayer structure formed by successively stacking at least a first high refractive index layer, a metal layer, and a second high refractive index layer, wherein, given that optical film thicknesses of the first high refractive index layer and the second high refractive index layer are x and y, respectively, and a geometrical film thickness of the metal layer is z, x, y and z satisfy the following formula (1): z ≤ 12.1 ⁢ exp ⁢ { - 1 2 ⁢ ( x - 120 145.17 ) 2 - 1 2 ⁢ ( y - 120 123.14 ) 2 } ( 1 )