PURPOSE: To improve coating and film-forming properties and obtain a homogeneous oxide film by converting a specific metallic compound (Ma), an organic compound (Lb), a monobasic acid (Ac), a resin acid (Rd) and an organic solvent (Se) into a solution under prescribed conditions.

CONSTITUTION: A metallic compound (Ma) selected from inorganic metallic salts and organometallic compounds, an organic compound (Lb) having 1-6 nitrogen and/or oxygen atoms as ligand atoms, a monobasic acid (Ac) having 1-2 alcoholic hydroxyl groups as a substituent group, a resin acid (Rd) selected from rosin, abietic acid and pimaric acid and an organic solvent (Se) are mixed so as to provide 0.1-4mol (Lb) and/or (Ac) based on 1 gram-atom (expressed in terms of metal) of (Ma) and contents of the respective (Rd) and (Se) accounting for 5-80wt.% in the total weight of the composition. When the (Se) is contained in mixing, heating is carried out or ammonia gas is made to exist to provide the objective solution.