An endoscope apparatus includes a light source apparatus, and a light-adjusting circuit. The light-adjusting circuit, based on a first image signal with a first wavelength band having a peak wavelength of a spectral characteristic and a second image signal with a second wavelength band having a peak wavelength of a spectral characteristic providing a value lower than that of the first image signal in the absorption characteristic and providing a suppressed scattering characteristic of the body tissue between a wavelength band providing a maximal value and a wavelength band for a minimal value in an absorption characteristic of a body tissue of a subject, provides a weight larger than that of the second image signal to the first image signal to calculate a light adjustment signal for adjusting a light amount in a light source apparatus and outputs the light adjustment signal.