A flight control device which controls an air vehicle flying around a structure, the flight control device including: a detection-position movement controller which causes the air vehicle to move to a detection position for detecting the designated sign, the detection position being given for the designated sign; a sign detector which, when the air vehicle arrives at the detection position, detects the identification code of the sign and measures a flight relative position which is a position of the air vehicle relative to the sign; and a designated-position adjustment unit which, when the sign detector detects the identification code of the designated sign, controls a flying position of the air vehicle, based on the flight relative position and a position of the via point relative to the designated sign, so that the flying position matches the via point.