Time-of-flight mass spectrometer and time-of-flight mass spectrometry method

A time-of-flight mass spectrometer comprising:

• a flight space formation electrode configured to form a flight space for separating ions derived from a component contained in a sample according to a mass-to-charge ratio;
• an ion detection unit configured to detect ions that have flown in the flight space;
• a voltage switching unit configured to switch a voltage to be applied to the flight space formation electrode from a first voltage for flying ions of a first polarity to a second voltage for flying ions of a second polarity at a given switching timing;
• an ion information acquisition unit configured to obtain a time of flight during which the ion flies in the flight space or a mass-to-charge ratio of the ion based on a detection result of the ions of the second polarity obtained by the ion detection unit after the voltage has been switched by the voltage switching unit;
• a correction information storage unit configured to store correction information related to a deviation in time of flight or a mass-to-charge ratio associated with an elapsed time from the switching timing;
• and
• a correction unit configured to correct the time of flight or the mass-to-charge ratio obtained by the ion information acquisition unit according to an elapsed time from the switching timing when the detection result of the ion is obtained using the correction information stored in the correction information storage unit.