PURPOSE: To accurately position an inspection device by vertically arranging a television camera and the inspection device in the parallel state of being separated in a prescribed distance set beforehand, matching the marking of the television camera with the marking of an object to be inspected and moving them.

CONSTITUTION: The television camera 20 and the inspection device 6 are mutually vertically arranged along a symmetry axis in the parallel state of being separated in the prescribed distance set beforehand. Then, the marking 31 of the television camera 20 is matched with the marking 32 of the object to be inspected and the television camera 20 and the inspection device 6 are mutually moved for a distance settable beforehand along the symmetry axis for connecting them. Thus, the inspection device such as an ultrasonic inspection head or the like for inspecting a reactor constituting member arranged inside a water pool for instance is accurately and surely positioned in a short time.