To obtain an alignment adjusting apparatus by which high-accuracy alignment adjustment of an optical system in a laser radar can be realized automatically.

An alignment adjusting apparatus is constituted in such a way that a part of scattered laser light received by a receiving optical system 13 is fetched, that the central position of the scattered laser light is detected, that a receiving optical system 10 is moved and controlled so as to correspond to the central position, and that the alignment of the transmitting optical system 10 with the receiving optical system 13 is adjusted. Consequently, even when a dislocation is generated in the optical axis of the transmitting optical system 10 and that of the receiving optical system 13 due to an environmental condition or the like, a laser radar is drive, and the scattered laser light is received by the receiving optical system 13. Then, the transmitting optical system 10 and the receiving optical system 13 are controlled so as to make the optical axis of the system 10 coincident with that of the system 13 is accordance with the central position of the scattered laser light, and the high-accuracy alignment adjustment of the laser radar is ensured.