Based on a parking frame certainty degree indicative of a degree of certainty about a presence is a parking frame in the travel direction of the vehicle and a parking frame entering certainty degree indicative of a degree of certainty about whether the vehicle enters the parking frame, a total certainty degree indicative of a total degree of the certainty of the parking frame certainty degree and the parking frame entering certainty degree is calculated. Acceleration of the vehicle is controlled depending on a manipulation amount of an accelerator pedal manipulated by a drive to instruct a driving force and is suppressed in a higher suppression degree as the total certainty degree is higher. Furthermore, the acceleration of the vehicle is suppressed in a lower suppression degree as the vehicle speed of the vehicle is higher.