To provide a reliable lithium secondary battery in which electrode reaction is performed with high density and high efficiency by covering current collecting leads of positive and negative electrode plates with an insulating layer having dissolution resistance to an organic electrolyte in a battery with a higher regard for input and output performance, and to solve a problem that a burr, a chip or the like in electrode processing (cutting) is one of causes of the internal short circuit of the battery, and the short circuit is further liable to be generated by a volume change of the electrode by charge and discharge, remarkably impairing the reliability of the battery.

The current collecting leads of the strip-like positive and negative electrode plates are covered with a synthetic resin selected from at least one of thermoplastic resin having dissolution resistance to an organic electrolyte and curing resin cross-linked by heating, ultraviolet irradiation or electron beam irradiation, or a mixture of the synthetic resin with an insulating filler as an insulating layer having a thickness of the thickness of a mixture layer or smaller.