To provide a brake mechanism causing no partial wear of a roller in regard to a brake mechanism provided in a movable body having a roller rolling on a rail.

The brake mechanism has a shaft 3 provided in the movable body and capable of rotating the roller 1, a brake member 7 provided on the shaft 3 and moving in a direction abutting on the rail, a spring (an energizing means) 9 energizing the brake member 7 in a direction separating away from the rail, and a driving means 10 provided on the shaft 3 for pushing the brake member 7 in the direction abutting on the rail by centrifugal force.