PURPOSE: To improve the portability and operability of the pen input type computer by using the stylus pen as an external storage device which stores the individual information.

CONSTITUTION: A nonvolatile flash memory 201 is incorporated in a stylus pen 200. Various data such as the individual dictionaries can be stored in the flash memory 201. In this case, the stylus pen 200 is the electro-magnetic induction system having a battery 305 for generating the electric field, which does not require the pen to be connected with the computer main body through the cables like the electrostatic induction system. Thus, the stylus pen 200 can be brought separately from the computer main body like floppy disks and memory cards and can hold the storage data of the flash memory 201 if the battery 305 is worked out. Accordingly, the stylus pen 200 can be used as the portable external storage device holding the individual information.