Distance information between an observation-target and each pixel of an imaging device is obtained in an endoscope apparatus. The endoscope apparatus includes a scope unit having an illumination-light illuminating unit and an imaging device, and a spectral image processing unit that generates a spectral estimation image signal of a predetermined wavelength by performing spectral image processing on an image signal output from the imaging device. The illumination-light illuminating unit illuminates the observation-target with illumination-light, and the imaging device images the observation-target by receiving light reflected from the observation-target illuminated with the illumination-light. The spectral image processing unit generates the spectral estimation image signal of the predetermined wavelength greater than or equal to 650 nm, as a spectral estimation image signal for obtaining distance information. Distance information representing a distance between the observation-target and each of the pixels is obtained based on the spectral estimation image signal for obtaining distance information.
