An all-solid-state battery was fabricated with LiCo0.3Ni0.7O2 fine powder as cathode materials. The LiCo0.3Ni0.7O2 fine powder was synthesized with oxalate decomposition methods and the average particle size of the powder was 2 mum diam. In the all-solid-state battery, a-60Li(2)S . 40SiS(2) powder, which was prepared by a mechanical milling process, was used as the solid electrolyte. The anode was metallic indium foil 0.127 mm thick. The charge-discharge cycling test of the battery was carried out under a constant current density of 64 muA cm(-2) with a 3.8 and 2.0 V charge-discharge criteria. The battery showed a rechargeable specific capacity of 98 mAh g(-1) based on the cathode materials. The charge-discharge cycle efficiency of the battery was almost unity after the second cycle.