A probe (10) comprises: an optical filter (141) which is disposed in front of a light-emitting end face of an optical fiber for irradiation (110) and transmits wavelength components of a measurement light for irradiating a site to be measured in a lumen out of light output from the optical fiber for irradiation (110) an optical filter (142) which is disposed in front of a light-entering end face of an optical fiber for receiving light (120) and transmits wavelength components other than the wavelength of the measurement light out of radiated light radiated from the site to be measured due to the site to be measured being irradiated with the measurement light and a flat light blocking member (143) which is disposed between the optical filter (141) and the optical filter (142) and has light blocking properties against the measurement light and the radiated light.
