Patent ID: 8653451

Claim:
A time-of-flight mass spectrometer comprising: an ion source for ionizing a sample by laser irradiation and accelerating generated ions by a delayed extraction method; a detector for detecting ions arriving at the detector after making a flight from the ion source; a storage portion holding an adjustment table in which a corresponding relationship between m/z values of known substances and values of given adjustment parameters including delayed extraction parameters associated with the delayed extraction method for the ion source is defined; a parameter adjusting portion for calculating values of the adjustment parameters correlated with any specified m/z value based on the adjustment table; a parameter setting portion for setting the delayed extraction parameters of the ion source based on the values of the adjustment parameters calculated by the parameter adjusting portion; and a flight time measuring portion for measuring flight times taken for the ions generated by the ion source, for which the delayed extraction parameters have been set, to reach the detector.