PURPOSE: To prevent a target from being lost by indicating an irradiation direction of laser light by a laser irradiation indicator with respect to a present position of a gun with signals from a laser irradiation detector and a synchronization generator irrespective of a turning angle of the gun.

CONSTITUTION: A laser irradiation indicator 2 receives a laser detection direction signal 5 with a detection signal reception part 21, and sends a detection signal to a controller 25 and a detection angle signal to a coordinate converter 23. A barrel presence angle 6 is sent from a synchronization transmitter 3 of the gun to the coordinate converter 23 where the detection angle signal is converted in coordinates to a car body reference on which the gun is mounted and is outputted to a memory 24 as a car body reference detection angle signal. In the controller 25, laser detection is recognized with the detection signal from the detection signal reception part 21, and the detection angle signal of a gun turret reference is indicated on an indicator 27 from a detection angle signal of the car body reference to which detection is performed and the gun present angle. Even when the gun is turned, the detection angle signal is corrected and indicated from the gun present angle to a detection angle of the gun reference. Further, provided an attitude angle of the car body is detected with an attitude detector, a target is prevented from being lost even when the car body is moved.