An amorphous, thin film of tin oxide is tested as an anode to replace lithium metal in a thin-film battery. Tin oxide shows irreversible discharge capacity in its initial state, and this gives rise to capacity loss on the first charge–discharge process. Thus, in terms of electrochemical properties, lithium metal is better than tin oxide as an anode for a thin-film battery. In some applications, however, thin-film batteries must withstand high fabrication temperatures (over 250°C to 260°C). Lithium metal film cannot be applied in such conditions due to its low melting point (181°C). Tin oxide is not only able to endure high fabrication temperatures but can also preserve its capacity for a large number of cycles after the initial discharge process. In this study, a thin film of amorphous tin oxide has been prepared by means of a sputtering method. Its suitability as an anode for a thin-film battery is examined. A thin film of LiMn2O4, prepared by a sol–gel method is used for the cathode.