Abstract: The instant disclosure relates to a manufacturing method of cathode catalyst, comprising the following steps. Initially, mix an organic medium with an iron-based starting material and a nitrogen-based starting material to form a mixture. Followed by adding a carbon material to the mixture and subsequently executing a heating process to form a solid-state precursor. Then mill the solid-state precursor to form a precursory powder. Successively, calcinate the precursory powder in the presence of NH3 to form a cathode catalyst. The cathode catalyst can reduce the activation energy of hydrogen ion reacting with oxygen to make water. The instant disclosure further provides an ozone-generating device.