PROBLEM TO BE SOLVED: To provide an inversion prevention mechanism having a relatively high freedom degree of a design, capable of surely maintaining an inversion prevention performance and achieving smooth winding rotation operation property.SOLUTION: An inversion prevention mechanism for a fishing reel comprises: an inversion prevention gear 12； an inversion prevention claw 20 which is engaged to the inversion prevention gear 12； and a cam 30 for performing control so as to engage and disengage the inversion prevention claw 20 to/from the inversion prevention gear 12. The cam 30 comprises: a friction holding body 31 which holds a rotor 10, and rotates with the rotor 10 by friction force with the rotor 10； and an energization member 32 which energizes the friction holding body 31 in a direction where holding force thereof is increased. The friction holding body 31 comprises: two holding parts 33, 34 for holding the rotor 10； a connection part 35 for connecting the two holding parts 33, 34 so as to be opened and closed freely； and an engagement part 36 formed on one of the two holding parts 33, 34 and engaged to the inversion prevention claw 20.SELECTED DRAWING: Figure 6【課題】本発明は、設計の自由度が比較的高い逆転防止機構であって、確実な逆転防止性能の維持を図りながら軽快な巻き取り回転操作性を実現することを課題とする。【解決手段】本発明の魚釣用リールの逆転防止機構は、逆転防止歯車１２と、逆転防止歯車１２に係合する逆転防止爪２０と、逆転防止歯車１２に逆転防止爪２０を係脱制御するカム３０とを備え、カム３０は、回転体１０に挟着し、回転体１０との摩擦力により回転体１０とともに回転する摩擦挟着体３１と、摩擦挟着体３１の挟着力が増す方向に付勢する付勢部材３２とを備え、摩擦挟着体３１は、回転体１０を挟む２つの挟着部３３，３４と、２つの挟着部３３，３４を開閉自在に連結する連結部３５と、２つの挟着部３３，３４の一方に形成されて逆転防止爪２０と係合する係合部３６とを備えていることを特徴とする。【選択図】図６
