The invention relates to an electromechanical brake force booster for a hydraulic vehicle brake system. The invention proposes that the brake force booster be formed with two restoring springs, one of which acts on an electromechanical actuator and the other of which restoring springs acts on a pedal rod. In the event of failure of the electromechanical actuator, only the other spring, which preferably has a relatively low spring force, must be compressed using muscle force. The force loss in the event of actuation exclusively by muscle force is reduced.