A secondary battery is configured to reduce contact resistance by improving structures of an electrode tab and a lead. The secondary battery with enhanced contact resistance includes an electrode assembly in which a cathode plate having a cathode tab, an anode plate having an anode tab and a separator are stacked alternately, a battery case accommodating the electrode assembly, and an anode lead electrically connected to the anode tab, wherein the battery case is sealed while accommodating the electrode assembly, and the anode lead and the cathode tab are exposed out of the battery case.