Mass spectrometer and mass spectrometry method

A mass spectrometry method for analyzing a sample using a mass spectrometry, the mass spectrometry including

• a frame which is a container having conductivity,
• a needle provided in the frame,
• an electrode provided apart from the needle in the frame,
• a detector configured to detect an ion amount based on electrons that are emitted from an ionized sample generated based on the sample,
• a controller configured to display a current amount measured by the detector,
• a first power supply configured to apply a first voltage to the needle,
• a second power supply configured to apply a second voltage to the electrode,
• a first current detection unit connected in series between a ground of the first power supply and the frame, and
• a second current detection unit connected in series between a ground of the second power supply and the frame,
• the mass spectrometry method comprising:
• as steps executed by the controller,
• (a) a step of starting mass analysis processing using the mass spectrometer;
• and
• (b) a step of determining, after the step (a), presence or absence of first electric discharge between the needle and a component of an ion source other than the electrode and presence or absence of second electric discharge between the needle and the electrode based on a result of comparing absolute values of current amounts transmitted from the first current detection unit and the second current detection unit with a threshold value.