PROBLEM TO BE SOLVED: To provide an ion generator which delivers long-life ions from a ceiling to a wide range of space to sterilize or deodorize the interior of a room.SOLUTION: An ion generator whose main body is buried in a ceiling is designed to generate ions from a ceiling surface. The main body of the ion generator includes a partition plate inside a cylindrical body case, ventilation means beneath the partition plate, electrostatic atomization means in an opening penetrating the partition plate, and a grille having a suction port and a blowoff port at the bottom of the body case. The electrostatic atomization means is composed of a Peltier element, an atomization part consisting of a discharge electrode adjoining a cooling surface of the Peltier element and a counter electrode, and a cooling fin adjoining a heat radiation surface, and the body case has a spiral shaped air passage provided inside thereof to create a whirling air flow, characterized in that the whirling air flow impinging upon the cooling fin has its direction changed to left and right diagonal downward directions while it is blown out from the blowoff port.
