A display apparatus composed of a main body and a display panel hinged to the main body is conveniently mounted on a ceiling of an automobile. The display panel is opened to a desired position to display information to a rear seat passenger, while it is closed and stays at a rest position when it is not used. Before the display panel is driven to the desired position, it is unlocked by bringing a holding device to a releasing state, and it is locked at the desired position by bringing the holding device to a holding state. At the holding state, a rotatable member connected to the display panel is gripped by the holding device, and the gripping force imposed on the rotatable member is removed at the releasing state. In this manner, the display panel is surely locked at an arbitrary position and is freely driven with a small driving force.