To realize a continuous measuring point causing no superposition or slip-off within a measuring range regardless of the distance between a measuring target and an optical probe without arranging a complicated mechanism.

The optical probe includes: a cylindrical probe outer cylinder, the optical fiber arranged in the probe outer cylinder and fixed to the probe outer cylinder, a light deflecting means capable of rotating the deflecting surface, which is arranged in the probe outer cylinder and deflects the light emitted from an optical fiber, centering around the optical axis of the light emitted from the optical fiber; the condensing lens arranged between the optical fiber in the probe outer cylinder and the light deflecting means and capable of being moved in the optical axis direction of the light emitted from the optical fiber; and a condensing lens moving means for moving the position in the optical axis direction of the condensing lens within a range satisfying fd1(2f) (wherein f is the focal distance of the condensing lens and d1 is the distance from the emitting part of the light of the optical fiber in the optical axis direction to the main point on the incident side of the condensing lens).