A spool (4) for preventing backlash includes a bobbin trunk (7a), a rear flange portion (18e), and a front flange portion (8). The front flange portion (8) includes a first protruding portion (17a) and a first oblique portion (17b) that protrudes upward and forward from a tip of the first protruding portion (17a). The rear flange portion (18e) includes a second protruding portion (18a) and a second oblique portion (318b) that protrudes upward and rearward from a tip of the second protruding portion (18a). The second oblique portion (318b) includes a chamfer that slants rearward so that a diameter thereof increases toward a rear end side of said second oblique portion (318b).
