The invention aims to provide a lithium secondary battery exhibiting the improved function of self safety in an abnormal state without sacrificing battery characteristics. To attain the object, in a lithium secondary battery comprising a positive electrode (3a, 3b), a negative electrode (2a, 2b), an electrolytic solution, and a separator, a plurality of positive electrodes (3a, 3b) and negative electrodes (2a, 2b) are arranged to construct an electrode structure which includes an outermost layer of electrode on which a back coat layer (11) is formed.