Method for operating redox flow cell and redox flow cell

The present invention provides a method for operating a redox flow cell that has a battery cell including an electrode used as a positive electrode and an electrode used as a negative electrode and a liquid flow path that allows an electrolyte to flow around each electrode, the method comprising: a step for supplying the electrode used as a negative electrode with a positive-electrode electrolyte in a state where no negative-electrode electrolyte is supplied thereto so as to allow a substance adhering to the electrode used as the negative electrode to dissolve in the positive-electrode electrolyte; and a step for removing ions generated due to dissolution of the substance with a filtering section provided in the liquid flow path.