A parking brake controller (19) activates an electric actuator (43) in response to operation of a parking switch (18) to hold a disc brake (31) to serve as a parking brake. If a failure (fault) is detected in the parking switch (18), the parking brake controller (19) activates the electric actuator (43) so as to hold the parking brake automatically upon detecting a condition that presumes the vehicle operator's intent not to drive any longer while the vehicle is at rest.