An ECU designates a value of a variation “Vunder” based on at least one of information about driver's operation, a velocity, and a road surface gradient when an actual velocity “V” is higher than a target velocity, sets a value of a variation “Vtarget” based on the designated value of the variation “Vunder” and the target velocity, adjusts the velocity of the vehicle to the velocity of the set value of the variation “Vtarget”, and determines whether the actual velocity “V” after the adjustment is a value not greater than the value of the variation “Vtarget”. Then, the ECU converges the velocity of the vehicle to the target velocity after it has been determined that the actual velocity “V” after the adjustment is a value not greater than the value of the variation “Vtarget”.