A fuel cell structure comprises a diffusion layer and/or a catalyst layer which are made of a carbonaceous porous material having a nano-size structure, such as carbon nanowall (CNW). A method of manufacturing the structure is also disclosed. The structure and method simplify the process of manufacturing a fuel cell electrode comprised of an electrode catalyst layer and a gas diffusion layer. The electrical conductivity of the catalyst layer is increased and the diffusion efficiency of the diffusion layer is improved, whereby the electricity generation efficiency of the fuel cell can be improved.