To provide a theft prevention apparatus for capable of informing to an outside occupant that the room switch of the vehicle is turned on under a locked restrained state or that an in-vehicle moving body detection sensor is turned on and taking a measure without degrading security by transmitting an information signal to the portable machine of an owner by a control means when the switch in the room or the detection sensor is detected to be turned on under the locked restrained state in the apparatus provided with the control means for shifting a vehicle door to the locked restrained state by prescribed operation.

In the theft prevention apparatus provided with the control means 30 for shifting the vehicle door to the locked restrained state by the prescribed operation, when the control means 30 detects that the vehicle room switches 10, 18, 27 or the in-vehicle moving body detection sensor 26 are detected to be turned on under the locked restrained state, the information signal is transmitted to the portable machines X, Y, and when the switches 10, 18, 27 or the detection sensor 26 are detected to be turned on under a non-locked restrained state, the information signal transmission to the portable machines X, Y is regulated.