A recording tape cartridge includes a set of two first guide wall portions formed in a direction orthogonal to a loading direction of the case into a drive device and between which a first protruding wall portion formed at a brake member is insertable, and a set of two second guide wall portions and a set of two third guide wall portions formed at regular intervals from the first guide wall portions in a circumferential direction. A second protruding wall portion at the brake member is insertable between the second guide wall portions, and the third protruding wall portion at the brake member is insertable between the third guide wall portions. An interval between the each first guide wall portion and the first protruding wall portion is denoted by α and an interval between the each second guide wall portion and the second protruding wall portion and an interval between the each third guide wall portion and the third protruding wall portion is denoted by β, “α≧2×β” is satisfied.