Patent ID: 7208728

Claim:
A mass spectrometer, comprising: an ionization source for generating ions; an ion transfer optics for transferring said ions; a first ion trap for trapping said ions and ejecting a part of the trapped ions with at least two m/z ranges sequentially; a second ion trap for trapping the ions ejected from said first ion trap and ejecting them in pulse form; and a time-of-flight mass spectrometer for accelerating the ions ejected from said second ion trap in the orthogonal direction to the introduction direction, wherein said first ion trap has four or more multipole rods to which a main RF voltage is applied, and vane electrodes which can form a harmonic potential in an axial direction of said multipole rods, and a supplemental AC voltage is applied to at least one of said vane electrodes for ejecting a part of the trapped ions.