An endoscope apparatus comprising: an illumination light source unit that emits illumination light used to illuminate a subject; an auxiliary measurement light source unit that emits auxiliary measurement light; an image pickup optical system, wherein an optical axis (Lm) of the auxiliary measurement light crosses an optical axis (Ax) of the image pickup optical system; and a processor, wherein the processor is configured to acquire a picked-up image that is obtained from image pickup of the subject illuminated with the illumination light and the auxiliary measurement light and includes at least two first and second spectral images having different wavelength components, to obtain a first arithmetic image from which a first noise component hindering detection of an irradiation position of the auxiliary measurement light is removed by first arithmetic processing based on the first and second spectral images, to detect the irradiation position of the auxiliary measurement light from the first arithmetic image, and to display a specific image in which a measurement marker set according to the irradiation position of the auxiliary measurement light is superimposed on the picked-up image, wherein in a case where the processor performs first binarization processing of obtaining a binarized first spectral image by binarizing the first spectral image and second binarization processing of obtaining a binarized second spectral image by binarizing the second spectral image, the processor is configured to perform first difference processing of the binarized first spectral image and the binarized second spectral image as the first arithmetic processing. an illumination light source unit that emits illumination light used to illuminate a subject; an auxiliary measurement light source unit that emits auxiliary measurement light; an image pickup optical system, wherein an optical axis (Lm) of the auxiliary measurement light crosses an optical axis (Ax) of the image pickup optical system; and a processor, wherein the processor is configured to acquire a picked-up image that is obtained from image pickup of the subject illuminated with the illumination light and the auxiliary measurement light and includes at least two first and second spectral images having different wavelength components, to obtain a first arithmetic image from which a first noise component hindering detection of an irradiation position of the auxiliary measurement light is removed by first arithmetic processing based on the first and second spectral images, to detect the irradiation position of the auxiliary measurement light from the first arithmetic image, and to display a specific image in which a measurement marker set according to the irradiation position of the auxiliary measurement light is superimposed on the picked-up image, wherein in a case where the processor performs first binarization processing of obtaining a binarized first spectral image by binarizing the first spectral image and second binarization processing of obtaining a binarized second spectral image by binarizing the second spectral image, the processor is configured to perform first difference processing of the binarized first spectral image and the binarized second spectral image as the first arithmetic processing.