NOVELTY - An all-solid-state lithium secondary battery (101) has positive electrode (120) containing positive electrode active material layer (103), negative electrode (121) containing negative active material layer (105), and solid electrolyte layer (104). Positive electrode active material layer consists of lithium cobaltate, and has ( alpha )-sodium ferrate-type crystal structure. Plane (018) is oriented in the positive electrode active material layer. Solid electrolyte layer consists of lithium lanthanum titanate, and has tetragonal crystal perovskite-type crystal structure.    USE - All-solid-state lithium secondary battery is used as power supply for mobile battery apparatus, power tool and electric vehicles.    ADVANTAGE - The all-solid-state lithium secondary battery has high charging/discharging characteristics, reliability and output characteristics. Since the expansion stress which arises in surface parallel to main surface of positive electrode active material layer is restrained, the fall of adhesion strength by repetition of charging/discharging cycle in the interface of positive electrode active material layer and solid electrolyte layer is suppressed. Therefore, the fall of charging/discharging cycle characteristics resulting from peeling of solid electrolyte layer is suppressed.    DETAILED DESCRIPTION - An all-solid-state lithium secondary battery has a positive electrode containing positive electrode active material layer, a negative electrode containing negative electrode active material layer which occlude-discharge lithium ion, and a solid electrolyte layer arranged between the positive electrode and the negative electrode. The positive electrode active material layer consists of lithium cobaltate, and has ( alpha )-sodium ferrate (NaFeO2)-type crystal structure. The plane (018) is oriented in the positive electrode active material layer. The solid electrolyte layer consists of lithium lanthanum titanate, and has tetragonal crystal perovskite-type crystal structure. The plane (110) or plane (102) is oriented in the solid electrolyte layer.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of all-solid-state lithium secondary battery.    All-solid-state lithium secondary battery (101)    Positive electrode active material layer (103)    Solid electrolyte layer (104)    Negative electrode active material layer (105)    Positive electrode (120)    Negative electrode (121)