A probe 3 includes an irradiation fiber 34, a light-collecting fiber 35, a covering member 37 that covers a side face of the fiber, a cap 40 that covers a distal end of the probe, a white plate 42 that is provided on a surface of the cap 40 facing the distal end of the fiber and that is used in calibration measurement by light emitted from the distal end of the fiber, and an adhesive member that adheres the cap 40 to the distal end of the probe 3 and is made of an adhesive member 43 having an adhesive strength with respect to the covering member 37, the adhesive strength decreasing by application of heat. In a light-irradiated portion of the white plate 42, heat is generated by being irradiated with light, and the adhesive 43 is melted by conduction of the generated heat from the white plate 42 to the adhesive 43.
