Ionization analysis method and apparatus

To be able to analyze the ions to accurate and sensitive. A first electrode 11 provided on the outer periphery of the dielectric made cylindrical body 13, into the cylindrical body 13, disposing a second electrode 12 with a gap between the inner surface of the tubular body 13. A first electrode 11 barrier discharge is generated inside the cylindrical body 13 by applying a high AC voltage between the second electrode 12. Idea to protrude outward from the distal end of the tubular body 13 to the tip portion 12a of the second electrode 12, the plasma jet by a barrier discharge without leaving the outside from the front end of the cylindrical body 13, cylindrical body 13 low thermal equilibrium plasma P is generated electron temperature at the tip outside the. By exposing the sample S to the thermal equilibrium plasma P, leaving particles from the sample S (atoms, molecules), without or disassemble polymerized, ionized soft. Generated ions are introduced into the mass spectrometer 50.