A method for manufacturing the electrode assembly includes: a first step of preparing a plurality of radical units, each of which is manufactured by alternately stacking an electrode and a separator; a second step of stacking the plurality of radical units to manufacture an electrode stack; and a third step of pressing an outer surface of the electrode stack to manufacture an electrode assembly on which a curved surface having a curvature radius is formed on the electrode stack, wherein, when the sum of bonding force remaining after the third step among bonding force between the electrode and the separator as bonding force generated before the third step is defined as F1, the sum of force by which the electrode and the separator are spread again so that shapes of the electrode and the separator return to shapes before the electrode stack is pressed in the third step is defined as R, and the sum of bonding force additionally generated between the electrode and the separator within the electrode assembly by the third step is defined as F2, expression: F1+R≤F2 is satisfied.