To provide a porous film having a high function and high performance and to realize an electrochemical display device having high performance.

A solvent resistant resin which contains at least one of pigment or dye and in which inorganic particles are dispersed is molded to form a film and then the film is made porous by eluting the inorganic particles by using an aqueous solution. Thereby, the porous film wherein the shapes and the filled state of the inorganic particles before elution are preserved and which is solidified in a continuous bubbles formed state is formed. The porous film is used in the electrochemical display device wherein display is performed by using electrochemical deposition and solution of metal. The porous film is interposed between a pair of substrates having electrodes formed on the surfaces opposite to each other and hollow holes of the porous film are filled with an electrolysis solution.