We fabricated and characterized mesoporous silica thin films on microreactor walls in order to perform more efficient heterogeneous catalytic reactions by using the mesoporous silica as a catalyst support. The structures of the films formed on the microreactor walls were characterized by comparing them with those of films formed on planar substrates under various conditions. Cross-section observations revealed that 120 nm thick SBA-16 films with a 3D cubic structure were uniformly coated across the microreactor. Furthermore, the microreactor was employed for a heterogeneous catalytic reaction in an organic solvent to determine its suitability. An aluminum-doped SBA-16 film was formed in the same manner inside the microreactor as a catalyst, although pure SBA-16 has little catalytic activity. The results of a cyanosilylation reaction showed that the reaction rate varied with the reactant flow rate. The specific characteristics are also discussed using a mathematical model of the mass transfer inside microreactors. (c) 2008 Elsevier B.V. All rights reserved.