PURPOSE: To produce on a substrate a transparent electroconductive film which is easy to make a minute pattern and is stable and has a high adhesive strength, by causing tin and nitric acid to react with each other in the presence of β-liketone until the tin is completely dissolved.
CONSTITUTION: The tin, the nitric acid and indium are caused to react with one another in the presence of the β-liketone and an organic solvent such as acetylacetone to produce a compound as shown in Fig. The ions of the tin and the nitric acid are bonded to each other by the action of the β-diketone to completely dissolve the tin to obtain a solution for making the transparent electroconductive film. If a solvent for dilutiog the solution contains 80% or more by weight of methanol or acetone, the scatter in the thickness of the film is reduced. The substrate is dipped in the solution to provide a thin solution film on the substrate. After the thin solution film is dried, it is baked to produce on the substrate the transparent electroconductive film which is easy to make a minute pattern and is stable and has a high adhesive strength.