A fabricating method of a unit structure for accomplishing an electrode assembly formed by a stacking method, and an electrochemical cell including the same are disclosed. The fabricating method of the electrode assembly is characterized with fabricating the unit structure by conducting a first process of laminating and forming a bicell having a first electrode/separator/second electrode/separator/first electrode structure, and conducting a second process of laminating first separator/second electrode/second separator one by one on one of the first electrode among two of the first electrodes.