Abstract: An optical integration element of the invention comprises a substrate possessing a light emitting element for emitting light, and a receiving sensor for receiving reflected light, an incident part composed of an optical transparent material for receiving the light from the light emitting element, a first reflecting part for reflecting the light entering from the incident part, a second reflecting part for reflecting by converting the light from the first reflecting part into nearly parallel light or convergent light, a condensing part for condensing the light from the second reflecting part, and an optical member forming an optical path transforming part for guiding the reflected light into the receiving sensor.