An image sensor includes a sensor substrate including a plurality of pixels for sensing incident light, and a nano-photonic microlens array including a plurality of nano-photonic microlenses corresponding respectively to the plurality of pixels, wherein each of the plurality of nano-photonic microlenses includes a plurality of nano-structures that are arranged two-dimensionally to condense incident light onto corresponding pixels, and a gap between two nano-structures that are arranged directly facing each other across a boundary between two adjacent nano-photonic microlenses is greater than an arrangement period of the plurality of nano-structures in each of the plurality of nano-photonic microlenses.