Provided is an optical measurement device capable of accurately discriminating between an abnormality caused by optical performance and an abnormality caused by a structural defect. The optical measuring device 2 receives a light source 22 that emits illumination light to the measurement object via the illumination fiber 31 and a first light that receives the return light of the illumination light reflected by the measurement object via the first light receiving fiber 32. Diffused light based on illumination light reflected by a reflection index member to be irradiated with illumination light received by the first light receiving unit 24 and the first light receiving fiber 32 via the first light receiving fiber 32, and light incident from the outside Based on a plurality of measured values of the diffused light based on the light incident from the outside received by the first light receiving unit 24 through the diffusion index member that transmits the uniform light and the first light receiving fiber 32, the measurement history And an arithmetic unit 291 that calculates characteristics.光学的な性能による異常と構成上の不具合による異常とを正確に判別することができる光学測定装置を提供する。光学測定装置２は、照明ファイバ３１を介して測定対象物へ照明光を出射する光源部２２と、第１受光ファイバ３２を介して測定対象物で反射した照明光の戻り光を受光する第１受光部２４と、第１受光ファイバ３２を介して第１受光部２４が受光した照明光の照射対象となる反射指標部材で反射した照明光に基づく拡散光、および、外部から入射される光を均一な光として透過させる拡散指標部材と第１受光ファイバ３２とを介して第１受光部２４が受光した外部から入射される光に基づく拡散光それぞれの複数の測定値に基づいて、測定履歴の特性を演算する演算部２９１と、を備える。
