To irradiate a measurement object uniformly with light.SOLUTION: Provided is a detecting device used for measuring the information of a measurement object, comprising: a light-emitting unit for emitting light； a branch unit for branching light emitted from the light-emitting unit and propagating in a first direction into a first irradiation light propagating in a second direction different from the first direction and a second irradiation light propagating in a third direction different from the first and second directions； a reflection optical system for reflecting the first and the second irradiation lights toward the measurement object so that a first region of the surface of the measurement object irradiated with the first irradiation light and a second region of the surface irradiated with the second irradiation light overlap each other； and a light-receiving unit for receiving light reflected inside of the measurement object irradiated with the first and second irradiation lights.SELECTED DRAWING: Figure 3【課題】被測定体に均一に光を照射する。【解決手段】被測定体の情報の測定に利用される検出装置であって、光を出射する発光部と、発光部から出射して第１方向に進行する光を、前記第１方向とは異なる第２方向に進行する第１照射光と、前記第１方向および前記第２方向とは異なる第３方向に進行する第２照射光とに分岐する分岐部と、前記被測定体の表面において前記第１照射光が照射される第１領域と、前記表面において前記第２照射光が照射される第２領域とが重なるように、前記第１照射光および前記第２照射光を前記被測定体に向けて反射する反射光学系と、前記第１照射光および前記第２照射光が照射された前記被測定体の内部で反射した光を受光する受光部とを具備する検出装置。【選択図】図３
