A sterilizing apparatus and an ion generating apparatus, which generate sufficient amount of cations in a short period of time and also maintain the amount of ions generated at a level that is harmless to the human body. The sterilizing apparatus and the ion generating apparatus optimize the position of an electrode to maximize the generation of active hydrogen. The ion generating apparatus includes a first electrode for generating hydrogen ions and a second electrode located such that the second electrode is separated from the first electrode by a designated distance for generating electrons and superoxide anions. The hydrogen ions generated from the first electrode react with the electrons generated from the second electrode to produce hydrogen atoms, and the hydrogen atoms react with the superoxide anions generated from the second electrode to sterilize the air.