A cruise control unit, configured to permit starting when an inter-vehicle distance to a front vehicle exceeds a determination threshold before a preset amount of time passes from a driver's operational input during a stopped state, calculates a first threshold that is updated to be larger according to a change in the inter-vehicle distance in the stopped state when the distance changes to be larger and a second threshold that is changed to be larger as a speed of the front vehicle is higher, and variably sets the determination threshold based on the larger of the two thresholds. It cancels the permission if a time passing from the operational input is determined longer than a cancel determination time for determining whether it is immediately after the driver's operational input and if the front vehicle is determined to stop or substantially stop at a speed lower than a preset vehicle speed.