A mass spectrometry method, using a mass spectrometry device including a sample platform on which a first sample and a position correction sample are disposed, an ion beam source configured to irradiate an ion beam toward a sample on the sample platform by applying a voltage to a deflection electrode of the ion beam source, a laser light source configured to irradiate laser light toward a region above the sample platform, and a mass spectrometry unit configured to analyse ionized particles, characterized in that the position correction sample having a stacked body, the stacked body including: a first layer including a first material; a second layer provided on the first layer, the second layer including a second material; and a third layer provided on the second layer, the third layer including a third material, the first material, the second material and the third material being mutually different, the stacked body having a first recess reaching the first layer from the third layer, the stacked body having a first surface, the first surface including a portion exposed via the first recess of the first layer, a portion exposed via the first recess of the second layer, and a portion exposed via the first recess of the third layer, wherein an angle between the first surface and an upper surface of the third layer is an obtuse angle, the method comprising: irradiating the ion beam on the first sample and using laser light to ionize first particles originating in the first sample; performing mass spectrometry of the ionized first particles; setting the voltage of the deflection electrode to a determined voltage value for irradiating the ion beam on the portion of the first surface where the second layer is exposed, and irradiating the ion beam on a portion of the first surface of the position correction sample while the voltage of the deflection electrode set to the determined voltage value; using laser light to ionize second particles originating in the irradiated portion of the first surface of the position correction sample; and performing mass spectrometry of the ionized second particles, and correcting an irradiation position of the ion beam with respect to the first sample based on a mass spectrometry result of the second particles by detecting whether a material included in a layer other than the second layer is detected by the mass spectrometry unit. a first layer including a first material; a second layer provided on the first layer, the second layer including a second material; and a third layer provided on the second layer, the third layer including a third material, irradiating the ion beam on the first sample and using laser light to ionize first particles originating in the first sample; performing mass spectrometry of the ionized first particles; setting the voltage of the deflection electrode to a determined voltage value for irradiating the ion beam on the portion of the first surface where the second layer is exposed, and irradiating the ion beam on a portion of the first surface of the position correction sample while the voltage of the deflection electrode set to the determined voltage value; using laser light to ionize second particles originating in the irradiated portion of the first surface of the position correction sample; and performing mass spectrometry of the ionized second particles, and correcting an irradiation position of the ion beam with respect to the first sample based on a mass spectrometry result of the second particles by detecting whether a material included in a layer other than the second layer is detected by the mass spectrometry unit.