All solid-state cells of In/LiCoO2 using the 80Li(2)S(.)20P(2)S(5) (mol%) glass-ceramics with high ambient temperature conductivity of about 10(-3) S cm(-1) as a solid electrolyte were fabricated, and the cell performance was investigated. Although an irreversible capacity was observed at the 1st cycle, the solid-state cell exhibited excellent cycling performances with the reversible charge-discharge capacities of about 100 mAh g(-1) even after 200 cycles.