PURPOSE: To attain the parallel jobs with an electronic notebook by providing sheet which has bus connectors on both sides and the holes through which the sheet can be restricted to a cover and plural information input devices which input plural types of information to a CPU via the sheet.

CONSTITUTION: The information inputted from an information input device 18 is processed by a CPU 12 via a bus connector 17. This processed information is stored in a RAM 13 which is nonvolatilized by a battery 15 and displayed or reproduced on an information display device 20. The device 18 can be attached and detached to and from a cover 11 via the connector 17. Thus plural devices 18 can be simultaneously packed and therefore used to a pocket bell, a pager, etc., in addition to an electronic calculator, a Japanese word input device, etc. Both a letter form 10 and a sheet 16 are restricted by the cover 11 through the holes of the form 10 and the sheet 16 and binders 19. As a result, the parallel jobs are attained with an electronic notebook.