To provide a vehicle anti-theft device with inexpensive of production cost in which a new device is not added for vehicle anti-theft.

The vehicle anti-theft device 1 is provided with STB 9a having interface 11 capable of installing B-CAS card 10 provided with discrimination code, ROM 24 for previously memorizing predetermined discrimination code and a control part for determining whether or not the B-CAS card 10 is installed on the interface 11, reading the discrimination code from the B-CAS card 10 when installed, checking it to the predetermined discrimination code memorized in the ROM 24 and outputting the discrimination code memorized in the B-CAS card when both discrimination codes are coincident with each other; and ECU 4 having a second memory part for memorizing predetermined discrimination code and a control part for checking the discrimination code outputted from the first control part to the discrimination code memorized in the second memory part and starting the vehicle when both discrimination codes are coincident with each other.