An image sensor includes an image sensor die, a light transmitting element, at least one anti-reflection coating and at least one anti-reflection structure. The image sensor die includes a photoelectric conversion layer and a micro lens layer. The micro lens layer is disposed above the photoelectric conversion layer for converging the light onto the photoelectric conversion layer. The light transmitting element is disposed above the micro lens layer, and a gap is formed between the light transmitting element and the micro lens layer, the light passes through the light transmitting element and then travels into the image sensor. The anti-reflection coating is at least disposed on an upper surface of the light transmitting element. The anti-reflection structure is disposed on at least one of a lower surface of the light transmitting element and the micro lens layer.