To provide an organic/inorganic composite in which an inorganic material aggregates to form a reticular structure having a wide size range from nano order to micron order in a polymer.

A method of manufacturing the organic/inorganic composite having a reticular structure formed from at least one of inorganic particles (B) selected from among a metal oxide, a nitride and metal particles in a polymer of a radically polymerizable monomer (A) includes: preparing a polymerization solution containing the radically polymerizable monomer (A), the inorganic particles (B), and a solvent (C); then polymerizing the polymerizable monomer (A) in the polymerization solution in such a temperature range that the polymerizable monomer (A) dissolves in the solvent (C) in the state of monomer and becomes insoluble in the solvent (C) after polymerization; and thereafter, removing the solvent (C).