To provide a brake arm support structure capable of absorbing brake torque generated during braking while securing high flexibility in all directions of an arm member, suppressing effects of the brake torque on an actuator side and a booster side and achieving a simple structure as a shaft member.

The brake arm support structure comprises a pair of sleeves 5D fitted to both shaft hole parts 5F, 2F formed on a brake arm 5 and a housing 2A and an arm shaft 5B fitted into the sleeves 5D, and inner end faces of the sleeves 5D are made abut on both end faces of a spherical bearing 2B arranged in the arm shaft 5B, respectively. Thus, while high flexibility in all directions of the arm member is secured by the spherical bearing 2B, brake torque generated during braking is effectively absorbed by the both end faces of the spherical bearing 2B on which the respective inner end faces of the sleeves 5D fitted to the brake arm 5 abut. As a result, turning force to the brake arm 5 can be alleviated and effects of the brake torque on the actuator and booster sides can be suppressed.