A solar cell including a substrate 1, a nanopillar 11 having diameter D1 connected to the substrate 1, and a nanopillar 12 having diameter D2 connected to the substrate 1 is characterized in that D2 is greater than D1 in order to realize a solar cell having, as the surface structure, a nanopillar array structure with which it is possible to prevent reflection within the broad wavelength region of solar light. A nanopillar array structure 21 formed from two types of nanopillars having different diameters has a point of minimum reflectivity of a nanopillar array structure formed from the nanopillar 11 having diameter D1 and a point of minimum reflectivity of a nanopillar array structure formed from the nanopillar 12 having diameter D2 and therefore, is capable of preventing reflection within the broad wavelength region of solar light.