Abstract: A theft-proof device, in which a main machine and a receiver are provided on a car to cooperate with an emitter carried on an owner of the car, so that the main machine of the car activates a theft-proof mechanism when the emitter on the owner exceeds the distance for receiving signals and activates an alarm for asking rescue when the car is driven after being stolen or robbed with the ignition lock being turned on, and the ignition lock then is turned off to prevent the car from initiating, the theft-proof devices can thus develop the function of robbery-proofing and asking rescue.