A brake apparatus stops a rotor of an external-rotor motor that drives the head or a joint of a home robot. Frictional torque is generated when a friction pad presses a rotor surface even when a power source is switched off. A posture of a moving part, such as the head, of the robot is not abruptly disturbed even though the power source is switched off. Since a light external force is applied to the moving part of the robot in the off state of the power source, a motion in a direction desired by the user takes places without being stiff. The motion of the head of the robot stops when the external force is removed. An intention of the user who touches the robot may be satisfied even when the power source of the robot is switched off.