Patent ID: 8022362

Claim:
An ionization device comprising: an ionization chamber provided with a discharge electrode and an opposing electrode installed inside a case having an ionization gas introducing inlet, with an orifice, which communicates with the outside of the ionization chamber, being formed through the opposing electrode at a position opposing a tip end of the discharge electrode; and a charging chamber, disposed adjacent to the ionization chamber on the orifice side thereof, having a charge object introduction portion, in which the charge object is charged by ions discharged from the orifice to be formed into ions, wherein an introducing inlet of the charge object introduction portion is disposed near the outlet of the orifice, and wherein a size of the orifice and a pressure between the ionization chamber and the charging chamber are so set that the charge object is sucked into the charging chamber by negative pressure generated by a gas, which contains ions, sprayed from the outlet of the orifice into the charging chamber with the pressure of the ionization chamber higher than that of the charging chamber.