A fabricating method of an electrode assembly comprising: forming a radical unit having a four-layered structure obtained by stacking a first electrode, a first separator, a second electrode, and a second separator one by one or a radical unit having an eight-layered structure formed by stacking the first electrode, the first separator, the second electrode, the second separator, the first electrode, the first separator, the second electrode and the second separator one by one; stacking at least two radical units one by one to form a unit stack part; and stacking a first auxiliary unit on a first distal end electrode, the first distal end electrode being the first electrode positioned at an uppermost or a lowermost portion of the unit stack part, when the first electrode being a cathode, and the second electrode being an anode, the first auxiliary unit being formed by stacking from the first distal end electrode, the separator, the anode, the separator and the cathode one by one, when the first electrode being the anode, and the second electrode being the cathode, the first auxiliary unit being formed by stacking from the first distal end electrode, the separator and the cathode one by one, wherein the radical unit is formed by attaching each electrode and the adjacent separator to each other, wherein the separator is coated with a coating material having adhesiveness, wherein both sides of the first separator facing the first electrode and the second electrode are coated with the coating material, and one side of the second separator facing the second electrode is coated with the coating material, characterized in that the cathode of the first auxiliary unit comprises: a current collector; and an active material coated only on one side facing the radical unit among both sides of the current collector. forming a radical unit having a four-layered structure obtained by stacking a first electrode, a first separator, a second electrode, and a second separator one by one or a radical unit having an eight-layered structure formed by stacking the first electrode, the first separator, the second electrode, the second separator, the first electrode, the first separator, the second electrode and the second separator one by one; stacking at least two radical units one by one to form a unit stack part; and stacking a first auxiliary unit on a first distal end electrode, the first distal end electrode being the first electrode positioned at an uppermost or a lowermost portion of the unit stack part, when the first electrode being a cathode, and the second electrode being an anode, the first auxiliary unit being formed by stacking from the first distal end electrode, the separator, the anode, the separator and the cathode one by one, when the first electrode being the anode, and the second electrode being the cathode, the first auxiliary unit being formed by stacking from the first distal end electrode, the separator and the cathode one by one, wherein the radical unit is formed by attaching each electrode and the adjacent separator to each other, wherein the separator is coated with a coating material having adhesiveness, wherein both sides of the first separator facing the first electrode and the second electrode are coated with the coating material, and one side of the second separator facing the second electrode is coated with the coating material, characterized in that the cathode of the first auxiliary unit comprises: a current collector; and an active material coated only on one side facing the radical unit among both sides of the current collector. a current collector; and an active material coated only on one side facing the radical unit among both sides of the current collector.