An electric brake system comprising a plurality of electric brake devices, each electric brake device including: a brake rotor; a friction member configured to operatively contact the brake rotor; a friction member actuator configured to cause the friction member to contact the brake rotor; an electric motor configured to drive the friction member actuator; a braking force estimation device configured to determine an estimate of a braking force generated by the friction member being pressed against the brake rotor; and a control device configured to perform follow-up control of the generated braking force by controlling the electric motor so that the generated braking force matches a braking force target value, the electric brake system further comprising: a controlled variable error estimation module configured to estimate, for each electric brake device, a controlled variable error that is a difference between the estimate of the braking force determined by the braking force estimation device and a braking force produced by the brake device having no functional degradation; and a controlled variable compensating module configured to, when the controlled variable error estimation module estimates the existence of the controlled variable error, distribute a braking force corresponding to the controlled variable error among the electric brake devices other than the electric brake device in which the existence of the controlled variable error is estimated so as to be added to the braking force target values of the respective electric brake devices, characterized in that in order to determine the braking force in the case where no functional degradation occurs, the controlled variable error estimation module uses a state transition formula expressing relationships among: a state variable including a motor rotation angle of the electric motor; a manipulated variable including voltage or current of the electric motor; a state transition matrix including electric actuator inertia of an electric actuator that includes the electric motor and the friction member actuator; and a controlled variable including a braking force. a brake rotor; a friction member configured to operatively contact the brake rotor; a friction member actuator configured to cause the friction member to contact the brake rotor; an electric motor configured to drive the friction member actuator; a braking force estimation device configured to determine an estimate of a braking force generated by the friction member being pressed against the brake rotor; and a control device configured to perform follow-up control of the generated braking force by controlling the electric motor so that the generated braking force matches a braking force target value, a controlled variable error estimation module configured to estimate, for each electric brake device, a controlled variable error that is a difference between the estimate of the braking force determined by the braking force estimation device and a braking force produced by the brake device having no functional degradation; and a controlled variable compensating module configured to, when the controlled variable error estimation module estimates the existence of the controlled variable error, distribute a braking force corresponding to the controlled variable error among the electric brake devices other than the electric brake device in which the existence of the controlled variable error is estimated so as to be added to the braking force target values of the respective electric brake devices, characterized in that in order to determine the braking force in the case where no functional degradation occurs, the controlled variable error estimation module uses a state transition formula expressing relationships among: a state variable including a motor rotation angle of the electric motor; a manipulated variable including voltage or current of the electric motor; a state transition matrix including electric actuator inertia of an electric actuator that includes the electric motor and the friction member actuator; and a controlled variable including a braking force. a state variable including a motor rotation angle of the electric motor; a manipulated variable including voltage or current of the electric motor; a state transition matrix including electric actuator inertia of an electric actuator that includes the electric motor and the friction member actuator; and a controlled variable including a braking force.