A spool for preventing backlash includes a bobbin trunk, a rear flange portion, and a front flange portion. The front flange portion includes a first protruding portion and a first oblique portion that protrudes upward and forward from a tip of the first protruding portion. The rear flange portion includes a second protruding portion and a second oblique portion that protrudes upward and rearward from a tip of the second protruding portion. A length in the radial direction of the second protruding portion is approximately the same as a length of the first protruding portion.