A hinge is mountable between two casing parts of a flexible electronic device, and includes a base seat and two rotating modules disposed at two sides of the base seat for respectively mounting the casing parts thereon. Each rotating module includes a primary support plate pivotably connected to the base seat, and a secondary support plate pivotably connected to the primary support plate. When the rotating modules are rotated from an initial position, where the secondary support plates are flush with the primary support plates for resting and supporting a flexible display thereon, to a terminal position, where the secondary support plates are turned away to provide a leeway, the casing parts are shifted from an unfolded state to a folded state.