An optical probe has an optical fiber, a deflecting element, and a protective tube. The optical fiber includes a glass filament having a first diameter for transmitting light between the proximal and distal ends thereof and a resin layer for covering the filament except for the distal end thereof. The deflecting element is made of glass in a circular form having a second diameter larger than the first diameter, and it is connected with the optical fiber and has an end-face having a normal vector whose angle relative to the central axis is larger than the critical angle. The protective tube surrounds a portion of the optical fiber and the entire length of the deflecting element and is adhered to the side of a deflecting optical element, whereas the inside diameter of the part covering the optical fiber is smaller than that of the part covering the deflecting element.