The mass spectrometer includes a sample stage, an irradiation unit that irradiates the sample with an energy beam and ionizes a component of the sample, an extraction electrode that extracts the ionized sample from the surface of the sample by a potential difference from the sample stage, an MCP that emits electrons in accordance with the ionized sample, an imaging part that acquires an image based on the electrons emitted by the MCP, and a control unit that controls operations of the irradiation unit, the extraction electrode, and the imaging part. The control unit changes the potential of the extraction electrode at a timing in accordance with the detection target component after the irradiation of the energy beam by the irradiation unit, and causes the imaging part to acquire an image as an analysis target in a period in accordance with the detection target component.

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