A facet region detection method for detecting a facet region of an SiC single-crystal ingot having a first surface and a second surface that is on a side opposite to the first surface, the facet region detection method comprising: a first irradiation step of irradiating the first surface of the SiC single-crystal ingot with light from a light source; a first fluorescence detection step of detecting fluorescence generated from the first surface of the SiC single-crystal ingot by the light with which the first surface is irradiated and obtaining the number of photons of the fluorescence; a first determination step of determining a facet region and a non-facet region on the first surface on the basis of the number of photons of the fluorescence detected in the first fluorescence detection step using a predetermined number value as a boundary; a second irradiation step of irradiating the second surface of the SiC single-crystal ingot with light from the light source; a second fluorescence detection step of detecting fluorescence generated from the second surface of the SiC single-crystal ingot by the light with which the second surface is irradiated and obtaining the number of photons of the fluorescence; a second determination step of determining a facet region and a non-facet region on the second surface on the basis of the number of photons of the fluorescence detected in the second fluorescence detection step using a predetermined number value as a boundary; and a calculation step of calculating an estimated position of a facet region inside the SiC single-crystal ingot between, and on the basis of, the facet region determined on the first surface in the first determination step and the facet region determined on the second surface in the second determination step. a first irradiation step of irradiating the first surface of the SiC single-crystal ingot with light from a light source; a first fluorescence detection step of detecting fluorescence generated from the first surface of the SiC single-crystal ingot by the light with which the first surface is irradiated and obtaining the number of photons of the fluorescence; a first determination step of determining a facet region and a non-facet region on the first surface on the basis of the number of photons of the fluorescence detected in the first fluorescence detection step using a predetermined number value as a boundary; a second irradiation step of irradiating the second surface of the SiC single-crystal ingot with light from the light source; a second fluorescence detection step of detecting fluorescence generated from the second surface of the SiC single-crystal ingot by the light with which the second surface is irradiated and obtaining the number of photons of the fluorescence; a second determination step of determining a facet region and a non-facet region on the second surface on the basis of the number of photons of the fluorescence detected in the second fluorescence detection step using a predetermined number value as a boundary; and a calculation step of calculating an estimated position of a facet region inside the SiC single-crystal ingot between, and on the basis of, the facet region determined on the first surface in the first determination step and the facet region determined on the second surface in the second determination step.