With regard to a function device formed by filling a porous structure with a functional material and a method for manufacturing the functional device, a technique for realizing a structure on a nanometer scale is not fully established. However, a method for manufacturing a function device characterized by including a step of providing a structure including columnar members and an area surrounding the columnar members, a step of removing the columnar members from the structure to form a porous body and a step of filling the porous body with a functional material allows various types of function device to be provided.