PURPOSE: To perform the same guiding control as that when a seeker is mounted, without mounting the seeker.

CONSTITUTION: Laser beams 5 are irradiated so as to be matched to an optical axis toward a target 2 from a laser transmitter 4, and the target 2 and a missile 3 are put in an area E where the laser beams are irradiated. The laser beams 5 are modulated to occulting frequency through encoder wheels 7, 8 and a characteristic correlative position signal to the target 2, which signal is coded in every square section in the case where the area E is divided in the shape of the square sections, is transmitted. In the side of the missile 3, a correlative position signal corresponding to a position in the area E is detected by a sensor 14. The correlative position of the missile 3 to the target 2 is discriminated by a decoder 15 on the basis of the correlative position signal, a correlative position-discriminating signal necessary for the correction of a course is transmitted to an autopilot 11, and steering gear is controlled.