A vibration damper can suppress squeals of a brake in a positive and reliable manner while consuming less electric power. The damper has a vibration detector for detecting vibrations of the brake, and a vibrator for applying vibrations to the brake pad based on a detection signal from the vibration detector. An actuator circuit for actuating the vibration detector and vibrator is connected to a car battery through a changeover switch and another switch. These switches are closed only if a brake switch is detecting that the brake is being applied and a vehicle stop detector is detecting that the vehicle is not moving. When the switches are closed, electricity is supplied to the actuator circuit, so that the vibration detector and vibrator are actuated by the actuator circuit. With this arrangement, the damper is kept deactivated when it is unnecessary or detrimental to apply vibrations to the brake. Since it is activated only when necessary, it consumes less electric power.