Provided is a coin-shaped lithium secondary battery including a positive electrode plate which is a lithium complex oxide sintered plate; a negative electrode plate which is a titanium-containing sintered plate; a separator interposed between the positive electrode plate and the negative electrode plate; an electrolytic solution with which the positive electrode plate, the negative electrode, and the separator are impregnated; and an exterior body having a closed space, the closed space accommodating the positive electrode plate, the negative electrode plate, the separator, and the electrolytic solution, the lithium secondary battery having a thickness of 0.7 to 1.6 mm and a diameter of 10 to 20 mm.