An illuminator includes a light-emitting element and a light extraction sheet which transmits light occurring from the light-emitting element. The light-emitting element includes a first electrode having a light transmitting property, a second electrode, and an emission layer between the first and second electrodes. The light extraction sheet includes a light-transmitting substrate having a first principal face and a second principal face, a first light extraction structure on the first principal face side of the light-transmitting substrate, and a second light extraction structure on the second principal face side of the light-transmitting substrate. The first light extraction structure includes a low-refractive index layer and a high-refractive index layer. The second light extraction structure is arranged so that light which is transmitted through the light-transmitting substrate and arrives at an incident angle of 40 degrees to 60 degrees has an average transmittance of 42% or more.