PURPOSE: To stop a vehicle at a right position to a crane by irradiating a reflecting member provided on the side face of the bed of the vehicle with the light of a beam sensor fixed to a transfer crane and making a pilot lamp 4e light to indicate the reception of reflected light from the reflecting member.

CONSTITUTION: A reflecting member 1 is provided on the side face of the bed of a vehicle T in corresponding to the center Q3 of the container loading section T1 of the vehicle T in the length direction and a beam sensor 2 is fixed to the cross girder G2 of a transfer crane TC so that the optical axis of the sensor 2 can be aligned with the center Q1 of a spreader beam SB in the length direction. When the light of the sensor 2 is projected upon the member 1 of a vehicle T running immediately below the crane TC, the vehicle T can be stopped at a right position to the crane TC and the centers Q3 and Q1 of the loading section T1 and beam SB can be aligned with each other with high accuracy, because the pilot lamp 31 of a stopping position informing means 3 lights when the means 3 receives reflected light from the reflecting member 1. Therefore, the loading/unloading work of containers can be carried out efficiently, because it is not required to adjust the position of the vehicle T to that of the crane TC.