A method of manufacturing a fishing-reel reel unit including a main body member having an opening includes forming the main body member having the opening and a processing reference, accommodating a bearing mounting part in the opening where the bearing mounting part has a bearing opening and an inner peripheral surface, accommodating a bearing in the bearing opening where the bearing is fixedly mounted on the inner peripheral surface, and machining the inner peripheral surface of the bearing mounting part after the bearing is fixedly mounted on the inner peripheral surface, based on the processing reference.