A boarding handrail disinfecting device includes: a cover member that is provided on a door for opening and closing an entrance of a vehicle, and that is disposed so as to closely face a boarding handrail provided on a periphery of the entrance when the door closes the entrance and withdrawn from the boarding handrail when the door opens the entrance; and an irradiation device that is provided on a surface of the cover member that faces the boarding handrail and irradiates the boarding handrail with ultraviolet light.