The present invention provides an optical sheet that excels in a light convergence function or a light diffusion function, has excellent brightness increase ratio in the desired angular direction, in particular the front surface direction, and greatly inhibits the side lobe, and a method for manufacturing such an optical sheet with good efficiency and high accuracy. The optical sheet has a substrate that has a first surface having formed thereon a peak-valley portion that converges and scatters light and an optical adjustment portion that differs in an optical property from the substrate. A plurality of the optical adjustment portions are formed at least in part of a non-passage portion for the light in the substrate in the case where a parallel beam falls from the first surface in a direction normal to a surface located opposite the first surface.