Patent ID: 7842919

Claim:
A Q-pole type mass spectrometer that is installed in a reduced pressure gas environment, wherein said Q-pole type mass spectrometer has a Q-pole region in which a high-frequency electric field is formed, said Q-pole type mass spectrometer is configured so that ions to be measured, having a predetermined linear energy, are injected into said Q-pole region from an ion source toward a collector, said Q-pole type mass spectrometer is configured so that the motion in an axial direction of the ions to be measured, advancing from said ion source to said collector, is controlled within the Q-pole region by generating force by which the ions to be measured accelerate in the Q-pole region from the ion source to the collector and by making the force continuously or intermittently act on the ions to be measured in the Q-pole region at the same time that the ions to be measured are subjected to mass separation in said Q-pole region by Coulomb force in the diameter direction generated by a quadrupole high-frequency field, said Q-pole type mass spectrometer is configured so that the control of the motion in the axial direction of the ions to be measured within said Q-pole region comprises using Coulomb force generated by an electric field formed by four Q-poles of said Q-pole type mass spectrometer, wherein said four Q-poles have equal DC potentials except for a DC potential U at the same position in the axial direction of each Q-pole of the four Q-poles, while each Q-pole of the four Q-poles has a different DC potential depending on the position in the axial direction, the four Q-poles have a resisting thin film formed thereon on at least part of the surfaces thereof such that the DC potential differs depending on the position of each Q-pole in the axial direction, and a high-frequency voltage V and DC voltage U are applied to the resisting thin film and the resisting thin film is formed spirally.