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 (21 1 ) subjecting the illumination light from the light source section to polarization separation a light reception side polarization separation element (22 1 ) 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 band 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 (22 2 ) receiving the transmitted or reflected light.
