The present invention provides a method for producing a manganese oxide nanoparticle dispersed material having steps of dissolving manganese nitrate in a polyamide acid solution (Step 1); forming a coating on the surface of the substrate using the polyamide acid solution containing manganese nitrate dissolved therein (Step 2); and carbonizing the polyamide acid and depositing manganese oxide nanoparticles by subjecting the coating to a heat treatment at a temperature not less than 600.degree. C. but not more than 1200.degree. C. (Step 3).