A supporting device according to an embodiment includes a holder, a supporter, and a controller. The holder holds a terminal device that includes a detection surface that detects an input operation by an operator. The supporter is connected to the holder and is movably provided so as to locate a terminal device at a predetermined position, the terminal device being held by the holder. The controller fixes the supporter in a state where the supporter is located at a predetermined position when the detection surface detects the input operation.
