a cruise control apparatus for a vehicle which is highly reliable and safe in operation . the cruise control apparatus includes a cruise control setting switch for setting cruise control ; a first switch operatively connected with the brake system in such a manner that it turns on and off the power supply to a throttle actuator , which acts to control the opening degree of a throttle valve , in response to brake release and application , respectively ; and a second switch for cancelling the setting of cruise control . the cruise control apparatus determines whether there is a fault in either one of the first and second switches which continues for more than a predetermined time when the vehicle is travelling at a speed higher than a predetermined level , and it inhibits the cruise control setting switch from setting cruise control when there is such a fault .