a transparent substrate that is transparent to light in a used wavelength band;

grid-shaped protrusions arranged on the transparent substrate at a pitch shorter than the wavelength of the light in the used band, extending in a predetermined direction, and having a reflective layer and a reflection suppressing layer in this order; and

a groove which is recessed in the transparent substrate between the grid-shaped protrusions to a depth of 60 nm or more and 120 nm or less and with a substantially U-shape that does not have a bottom surface, wherein

the reflection suppressing layer is a mixture of a light absorbing material and a dielectric,

the reflection suppressing layer width in a direction orthogonal to the predetermined direction becomes smaller toward the tip side,

the polarizing plate has a transmission axis reflectance of 1% or less in the green wavelength band, and

the reflection suppressing layer contains Fe or Ta with Si, and has a concentration distribution in which the concentration of Fe or Ta is inclined in the layer thickness direction.