Time-of-flight mass spectrometer

A time-of-flight mass spectrometer comprising:

• an ion ejection unit;
• a flight tube that forms a space in which ions ejected from the ion ejection unit fly;
• a vacuum chamber in which the flight tube is enclosed;
• a temperature control unit that controls a temperature of the flight tube;
• and
• a temperature control section that controls a temperature control operation by the temperature control unit based on an indirectly or directly measured temperature of the flight tube and a target temperature,
• the time-of-flight mass spectrometer further comprising:
• a temperature sensor that measures an ambient temperature, which is a temperature outside the vacuum chamber;
• a prediction unit that predicts, based on the ambient temperature and the target temperature, a possibility that the temperature of the flight tube will not reach the target temperature or will not fall within a predetermined allowable temperature range including the target temperature even with the temperature control using the temperature control unit;
• and
• a notification unit that performs a notification to a user according to a prediction result by the prediction unit.