An ion generating component (4) is provided with a grounding electrode (42) and a high-voltage electrode (43) on an insulating board (41); an insulating film (44) formed on a surface of the grounding electrode (42); and a linear electrode (45). The grounding electrode (42) is formed on the periphery of the insulating board (41), and is provided with a pair of leg parts (42a, 42b) parallel to the linear electrode (45) by having the linear electrode (45) in between. Further, the grounding electrode (42) is provided with a contact part (42c) with which a terminal (5b) is brought into contact, and an insulating case contact part (42d) with which an upper side resin case (3) is brought into contact. Substantially on the entire plane of the insulating board (41), the insulating film (44) is formed by leaving the high-voltage electrode (43), the contact part (42c) of the grounding electrode (42), and an insulating case contact part (42d).