A failure detection device according to the present disclosure is a failure detection device that detects a failure of an input interface device detecting a position on a screen, the position being selected by an input operation. The failure detection device includes a memory, and a controller connectable to the input interface device. The controller acquires position information of a predetermined selected region on a screen, calculates a counted number of determinations that the predetermined selected region is not present on a selected position on the screen, and determines that an input interface device is in an abnormal state in a case where the counted number satisfies a predetermined condition.