In an apparatus for effecting at least one of display and input, a sheet-like member is designed so that it has rigidity only when the rigidity is required for input or display and can be bent or rolled at other times. An apparatus 100 capable of effecting at least one of display and input includes a flexible sheet-like member 200 which effects at least one of display and input. The apparatus 100 further includes rigidity adjusting means for at least partially changing rigidity of the sheet-like member as desired.