Image sensor

An image sensor includes a semiconductor substrate having opposite first and second surfaces, a wiring structure on the first surface of the semiconductor substrate, and a refractive structure on the second surface of the semiconductor substrate. The refractive structure includes a first anti-reflective layer on the second surface of the semiconductor substrate, a refractive pattern on the first anti-reflective layer, an insulation layer on the first anti-reflective layer, and a second anti-reflective layer on the refractive pattern and the insulation layer. The refractive pattern includes first refractive parts spaced apart from each other in a first direction parallel to the second surface of the semiconductor substrate, and the insulation layer fills spaces between the first refractive parts.