A biological measurement apparatus 1 includes: an endoscope 11 including a treatment instrument insertion channel 26 provided inside an insertion portion 21 a pump 62 that delivers water into the treatment instrument insertion channel 26 an optical system 72, etc., that guide light from a light source 64 that emits light in a predetermined wavelength band into the water delivered into the treatment instrument insertion channel 26 and a spectroscope 65 that detects return light resulting from the light passing through the water, falling on and being reflected by an object and returning while passing through the water when the water is delivered from the pump 62.
