A lithium secondary battery includes: a positive electrode including a positive-electrode active material layer; a negative electrode including a negative-electrode active material layer; and an ion conductor being lithium ion conductive and interposed between the positive electrode and the negative electrode. The positive-electrode active material layer is composed of lithium cobaltate, and has an α-NaFeO2 type crystal structure. The positive-electrode active material layer is composed only of first regions oriented in the (110) plane and second regions oriented in the (018) plane, the first regions and the second regions being mixedly present in the xy plane of the positive-electrode active material layer, where x and y axes are defined as two axes that are parallel to the principal face of the positive-electrode active material layer, and a z axis is defined as an axis perpendicular to the principal face.