A supported catalyst for aldehyde coupling reaction, comprising a carrier having supported thereon a catalyst comprising at least one azolium compound selected from the group consisting of a thiazolium salt, an imidazolium salt, a benzimidazolium salt and a triazolium salt, the azolium compound having, at a nitrogen atom thereof, a substituent selected from the group consisting of an aliphatic group having 6 or more carbon atoms and an aromatic group having 6 or more carbon atoms.