An endoscope observation system includes a light source section generating different types of light in at least partly different wavelength bands for observation of a polarized light-based observation image and for observation of a non polarized light-based observation image, respectively an irradiation side polarization separation element subjecting the illumination light from the light source section to polarization separation a light reception side polarization separation element performing polarization separation, in a particular wavelength band of the light from the observation target, by transmitting polarized light with a predetermined polarization component while reflecting polarized light with a polarization component other than the predetermined polarization component, and in a wavelength bend other than the particular wavelength band, exhibiting same transmission and reflection characteristics for both polarized light and non polarized light and an image pickup element receiving the transmitted or reflected light.
