An ion generating element of the present invention includes a discharge electrode and an inductive electrode, both of which are provided so as to face each other with a dielectric body sandwiched therebetween, and a heater electrode which warms the ion generating element by Joule heat produced because of a passage of an electrical current. A distance between the discharge electrode and the heater electrode is larger than that between the discharge electrode and the inductive electrode, and further a shield electrode having a connection for ground is provided between the heater electrode and the inductive electrode on a surface of the dielectric body at a side on which the inductive electrode is provided. Hence, it is possible to prevent a leak to the heater electrode at low cost, while giving consideration towards safety.