An improved optical fiber holder is provided, including: a tubular member (3) for fitting over an optical fiber bundle (1) consisting of a bundle of plural optical fibers (11) to prevent the optical fibers (11) from separating from each other; and a pressing structure (5) for exerting a pressing force on the optical fiber bundle (1) in a direction perpendicular to a longitudinal direction of the optical fiber bundle (1) to press the optical fiber bundle (1) against an inner periphery (3a) of the tubular member (3).