An organism light measuring device is characterized by including a light illuminating probe, a light receiving probe, a probe holder for holding the probes, and a nose pad provided to the probe holder so as to illuminate the deep/bottom region of the brain of a human being stably with good reproducibility.  The light illuminating probe is placed so that the glabella is illuminated by light from approximately perpendicular direction.  The probe holder has a mechanism such that after the probe holder is secured to the organism by means of the nose pad so that no light enters the eyeballs of the subject, illumination of the organism with light from the light illuminating probe is started.  The probe holder also has a mechanism for preventing the probes from poking the eyeballs.
ORGANISM LIGHT MEASURING DEVICE