Time-of-flight mass spectrometer

A time-of-flight mass spectrometer including an ion ejector configured to eject a measurement-target ion into a flight space by imparting acceleration energy by an effect of an electric field created by a voltage applied to an electrode, and a high-voltage pulse generator configured to apply a high-voltage pulse for ion ejection to the electrode, wherein:

• the high-voltage pulse generator includes:
• a) a DC power source configured to generate a high DC voltage;
• b) a switch circuit configured to generate the high-voltage pulse by switching the high DC voltage generated by the DC power source, and to output the high-voltage pulse to a voltage-output end, the switch circuit including one or more plus-side switching elements and one or more minus-side switching elements connected in series, where each of the plus-side switching elements is configured to output a plus-side voltage generated by the DC power source to the voltage-output end when in an ON state, and each of the minus-side switching elements is configured to output a minus-side voltage generated by the DC power source to the voltage-output end when in an ON state;
• c) a switching element driver configured to turn on/off the switching elements according to a pulse signal for ejecting ions, the switching element driver including a first switching element driver configured to respond to a first pulse signal and electrically charge a control terminal to a voltage which turns on the plus-side switching element or a voltage which maintains the plus-side switching element in the ON state, as well as a second switching element driver configured to respond to a second pulse signal and electrically charge the control terminal to a voltage which turns on the minus-side switching element or a voltage which maintains the minus-side switching element in the ON state;
• d) an adjustment circuit including a resistor inserted in series with the control terminal on a signal path extending from the switching element driver to the control terminal, the adjustment circuit configured to make the voltage at the control terminal be a voltage having a predetermined transient characteristic;
• and
• e) a controller configured to generate the first pulse signal and the second pulse signal in addition to the pulse signal for starting the output of the high-voltage pulse, so as to recharge the control terminal of the plus-side switching element or the minus-side switching element which is in the ON state.