The infiltration of a liquid from a gap between a one-way clutch assembly of a spinning reel and a reel body can be more certainly prevented. An inversion preventing tool (50) inhibiting the rotation of a rotor (3) in a line discharging direction is equipped with a one-way clutch assembly (51), a cover member (52), a first sealing member (53), and a second sealing member (54). The one-way clutch assembly (51) is coupled with a coupling unit (2e) of a reel body (2) to be able to be attached and detached. The cover member (52) is in the form of a rigid body including: a bottom unit (64a) covering the overall surface of the one-way clutch assembly (51)； and a tube unit (64b) covering the outer circumference (51a) of the one-way clutch assembly (51) and the outer circumference of the coupling unit (2e). The first sealing member (53) seals a gap between the coupling unit (2e) and the tube unit (64b). The second sealing member (54) seals a gap between a mounting unit (33a) of the rotor (3) and the bottom unit (64a) of the cover member (52).
