Patent ID: 8692191

Claim:
A mass spectrometer comprising: an ion source for ionizing a sample to create ions; an ion storage portion for storing the created ions and ejecting the stored ions as pulsed ions; a first mass analyzer for selecting first desired ions from the pulsed ions ejected from the storage portion based on mass-to-charge ratio; a collision cell for fragmenting some or all of the first desired ions into product ions; a second mass analyzer for selecting second desired ions from the first desired ions and the product ions based on mass-to-charge ratio; a detector for detecting the second desired ions; and a controller for providing control such that those of the first desired ions which have larger masses have larger kinetic energies in the direction of an optical axis in the first mass analyzer and that those of the second desired ions which have larger masses have larger kinetic energies in the direction of the optical axis in the second mass analyzer.