To provide an aircraft warning light inspecting device that can reduce the burden and danger of an aircraft warning light by an inspector and to make inspection efficient.

An optical sensor 22 and the like receive light from an aircraft warning light blinked or lighted at night, and generates a detection signal S24 corresponding to a light received result. A twenty-four hour timer 25 judges day or night and generates a day/night judgment signal S25 corresponding to a judged result. An abnormality judgment signal indicating abnormality is outputted in the case of the aircraft warning light not being lighted at night from the detection signal S24 and the day/night judgment signal S25. An AND circuit stores a polemid valve 28 in a single storage box, which, upon input of the abnormality judgment signal indicating abnormality, moves a hinge 29 to the left side and releases support of a weight 31 to hang red cloth down.