There is provided an electrode assembly having increased degrees of structural freedom in the thickness direction thereof. The electrode assembly includes negative and positive electrodes alternately stacked with separators interposed therebetween, wherein the electrode assembly is formed by stacking N electrode stacks where N is a natural number equal to or greater than 2, each of the electrode stacks comprises electrodes having the same area and stacked with separators interposed therebetween, and neighboring electrode stacks of the electrode stacks have different electrode areas, wherein a first electrode stack of the electrode stacks is formed by stacking unit cells respectively including an odd number of electrodes, and the other electrode stacks stacked on the first electrode are formed by stacking unit cells respectively including an even number of electrodes.