A wavelength selection filter comprising: a projection-depression structure layer having, on a surface thereof, a projection-depression structure including a plurality of projection-depression elements being projections or depressions , the projection-depression elements being spaced from each other at a subwavelength period and arranged in a form of a two-dimensional lattice, wherein the two-dimensional lattice is a tetragonal lattice or a hexagonal lattice; a high refractive index layer positioned on the projection-depression structure and having a surface shape following the projection-depression structure, the high refractive index layer including a first high refractive index section positioned on a bottom of the projection-depression structure and a second high refractive index section positioned on a top of the projection-depression structure; and a filling layer filling surface projections and depressions of the high refractive index layer , wherein n 1 > n 2 , n 1 > n 3 , and R 1 + R 2 > 1 , a value of T1 × {n1 × R1 + n2 × (1 - R1)} is a first parameter, a value of T2 × {n1 × R2 + n3 × (1 - R2)} is a second parameter, and a ratio of the second parameter to the first parameter is 0.7 or more and 1.3 or less, where T1 is a thickness of the first high refractive index section, T2 is a thickness of the second high refractive index section, n1 is a refractive index of a material of the high refractive index layer , n2 is a refractive index of a material of the projection-depression structure layer , n3 is a refractive index of a material of the filling layer , R1 is an area ratio occupied by the first high refractive index section in a cross section including the first high refractive index section and orthogonal to a thickness direction thereof, and R2 is an area ratio occupied by the second high refractive index section in a cross section including the second high refractive index section and orthogonal to a thickness direction thereof. a projection-depression structure layer having, on a surface thereof, a projection-depression structure including a plurality of projection-depression elements being projections or depressions , the projection-depression elements being spaced from each other at a subwavelength period and arranged in a form of a two-dimensional lattice, wherein the two-dimensional lattice is a tetragonal lattice or a hexagonal lattice; a high refractive index layer positioned on the projection-depression structure and having a surface shape following the projection-depression structure, the high refractive index layer including a first high refractive index section positioned on a bottom of the projection-depression structure and a second high refractive index section positioned on a top of the projection-depression structure; and a filling layer filling surface projections and depressions of the high refractive index layer , wherein n 1 > n 2 , n 1 > n 3 , and R 1 + R 2 > 1 , a value of T1 × {n1 × R1 + n2 × (1 - R1)} is a first parameter, a value of T2 × {n1 × R2 + n3 × (1 - R2)} is a second parameter, and a ratio of the second parameter to the first parameter is 0.7 or more and 1.3 or less, where T1 is a thickness of the first high refractive index section, T2 is a thickness of the second high refractive index section, n1 is a refractive index of a material of the high refractive index layer , n2 is a refractive index of a material of the projection-depression structure layer , n3 is a refractive index of a material of the filling layer , R1 is an area ratio occupied by the first high refractive index section in a cross section including the first high refractive index section and orthogonal to a thickness direction thereof, and R2 is an area ratio occupied by the second high refractive index section in a cross section including the second high refractive index section and orthogonal to a thickness direction thereof. <EOS>