Abstract: Disclosed is an optical fiber gyroscope comprising a fiber coil composed of a lengthy optical fiber wound therearound in a predetermined number of turns, a coupler for optically coupling an optical fiber led from a light source and an optical fiber led to a photodetector, and an optical IC chip arranged between the fiber coil and the coupler and provided with a phase modulator and a polarizer mounted on an optical waveguide, the optical fiber gyroscope further comprising a fiber coil reel around which the lengthy optical fiber for constructing the fiber coil is wound in the predetermined number of turns, a coupler reel around which the optical fibers led in both directions from the coupler are wound in a predetermined number of turns, and a housing member including a plurality of compartments (reel-placing region, frame, frame) for accommodating at least the both reels, the light source, and the optical IC chip.