PURPOSE: To provide the commencement inspection method for unattended running vehicle which improves the reliability of diagnosis of an ultrasonic distance sensor.

CONSTITUTION: When a vehicle body 51 will be started, the vehicle body 51 is arranged in the internal angle part of a wall face 60 so that a left face 51C faces the wall face 60, and the operation of a left face ultrasonic distance sensor 53C is diagnosed. The vehicle body 51 is turned so that a front 51A and a right face 51B face the wall face 60, and operations of a front ultrasonic distance sensor 53A and a right face ultrasonic distance sensor 53B are diagnosed. Then, the vehicle body 51 is turned again and is started.