<p>It is possible to suppress charge object destruction and non-target particle generation and increase charge efficiency. An ionization device includes an ionization chamber (1) and a charging chamber (20). The ionization chamber (1) has a discharge electrode (6) and an opposing electrode (10) in an interior (4) of a case having an ionizing gas introducing opening (14). The opposing electrode (10) has an orifice (8) communicating with outside and formed at a position opposing to the tip end of the discharge electrode (6). The charging chamber (20) is arranged adjacent to the orifice (8) side of the ionization chamber (1). An introduction opening (28) of a charge object introduction portion of the charging chamber (20) has a slit shape and is arranged so as to surround an exit of the orifice (8) at the position near the exit of the orifice (8). The ionization chamber (1) has a higher pressure than the charging chamber (20) and the size of the orifice (8) is set so that the charge object is pulled into the charging chamber (20) from the introduction opening (28) by a negative pressure generated when a gas containing ions is sprayed from the exit of the orifice (8) into the charging chamber (20).</p>
