To provide a vehicle circumference monitoring device capable of providing proper warning information to a driver without degrading distance measuring performance for small distance.

This vehicle circumference monitoring device for monitoring the vehicle circumference is provided with a transmitting antenna 2 mounted inside a vehicular door mirror 16 for radiating transmission waves through the mirror surface of the door mirror, and a receiving antenna 3 for receiving reflecting waves from an object present in the vehicle circumference through the mirror surface of the door mirror. In this case, a radio wave turnaround restraining member for restraining a radio wave component turning around from the transmitting antenna 2 to the receiving antenna 3 is provided. The radio wave turnaround restraining member is formed with a radio wave absorbing material 9 mounted between opening surfaces 8 respectively corresponding to the transmitting and receiving antennas of the door mirror, a metal plate mounted between the transmitting and receiving antennas, a radio wave absorbing material mounted between the antennas and the door mirror excluding the front faces of the opening surfaces respectively corresponding to the transmitting and receiving antennas of the door mirror, or a matching layer formed between the antennas and the door mirror.