In a fixing tool for fixing a fiber holding member to an optical fiber, a tool body receives the optical fiber and the fiber holding member. In this event, the fiber holding member is disposed on a first specific part of the optical fiber. A positioning device fixes a second specific part of the optical fiber to the tool body in the state where the optical fiber and the fiber holding member are received in the tool body. The second specific part is a portion between the first specific part and a longitudinal end face of the optical fiber.