An endoscope apparatus 1 includes a light source apparatus 4, a CCD 2, and a video processor 7 that generates an image signal based on an image pickup signal from the CCD 2, an observation monitor 5, and a light-adjusting circuit 43. The light-adjusting circuit 43, based on a first image signal P1 with a first wavelength band having a peak wavelength of a spectral characteristic and a second image signal P2 with a second wavelength band having a peak wavelength of a spectral characteristic providing a value lower than that of the first image signal P1 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 P2 to the first image signal P1 to calculate a light adjustment signal for adjusting a light amount in a light source apparatus 4 and outputs the light adjustment signal.
