A filter structure capable of efficiently separating water and oil using wettability is provided. The filter structure according to an exemplary embodiment of the present invention includes a first filter layer including a plurality of openings, a second filter layer including a plurality of openings and positioned so as to be overlapped with the first filter layer at a distance from each other, and a hydrophobic polymer layer formed on surfaces of the first filter layer and the second filter layer. The first filter layer and the second filter layer include surfaces each having a dual-scale protrusion and depression structure as a combination of a micro-scale structure and a nano-scale structure, and the hydrophobic polymer layer is formed along curves of the protrusion and depression structure.