A brake device system including brake devices to be mounted to a vehicle at each of four quadrants about the center of gravity on a plane orthogonal to a direction of the gravity that acts on the vehicle, each brake device comprising a brake rotor, a friction pad configured to come into contact with the brake rotor and generate a braking force, a friction pad driving assembly (Mk) configured to cause the friction pad to come into contact with the brake rotor, and a control device configured to control the braking force by using the friction pad driving assembly (Mk), wherein the control device includes: a braking/stoppage determination section configured to cause the friction pad to come into contact with the brake rotor of each of the brake devices, and determine whether or not the vehicle is braking or being kept stopped; and a heat conduction suppressing section configured to, when the braking/stoppage determination section has determined that the vehicle is braking or being kept stopped, reduce the braking force of a part of the plurality of brake devices, thereby to reduce heat conductivity of brake friction heat to the friction pad driving assembly (Mk), wherein the heat conduction suppressing section is configured to have a function of, while the braking force of the part of the plurality of brake devices is reduced, compensating for the reduction of the braking force by using the other brake devices, thereby to keep a total sum of the braking forces of all the brake devices equal to a value in a case where the braking force of the part of the plurality of brake devices is not reduced, and wherein the control device, when causing the heat conduction suppressing section to operate, is configured to set a braking force of each brake device so that a turning moment of the vehicle, that is caused by an operation of the brake device, becomes lower than or equal to a predetermined value. a braking/stoppage determination section configured to cause the friction pad to come into contact with the brake rotor of each of the brake devices, and determine whether or not the vehicle is braking or being kept stopped; and a heat conduction suppressing section configured to, when the braking/stoppage determination section has determined that the vehicle is braking or being kept stopped, reduce the braking force of a part of the plurality of brake devices, thereby to reduce heat conductivity of brake friction heat to the friction pad driving assembly (Mk), wherein the heat conduction suppressing section is configured to have a function of, while the braking force of the part of the plurality of brake devices is reduced, compensating for the reduction of the braking force by using the other brake devices, thereby to keep a total sum of the braking forces of all the brake devices equal to a value in a case where the braking force of the part of the plurality of brake devices is not reduced, and wherein the control device, when causing the heat conduction suppressing section to operate, is configured to set a braking force of each brake device so that a turning moment of the vehicle, that is caused by an operation of the brake device, becomes lower than or equal to a predetermined value.