freely applied to fulfill the purpose 0037 fig5 is a diagram the state in which memory cards 520 and 530 of different specifications are inserted into a card slot 510 one at a time in the external storage device of the present invention first it is assumed that the external storage device of the present invention is provided with a space so as to accommodate memory cards of plural specifications such as mini sd card a mmc and a memory stick one at a time that is it is assumed that when the external storage device of the present invention is implemented and thereafter a memory card supported by the external storage device is inserted into the card slot 510 there is no case where the memory card cannot be used due to the limitation of the internal space of the card slot 510 the external storage device supports memory cards of plural specifications as described above when a memory card is inserted into the card slot the external preferably detect the specification of the inserted memory card that is the specification of a mini sd card a mmc or a memory stick the detection function can be implemented in various ways fig5 illustrates the case where a plurality of detection terminals are disposed in the card slot 510 the external storage device shown in fig5 can accommodate a mini sd card 520 and a mini memory stick card 530 when one of them is inserted into the card slot 510 the external storage device can determines whether the inserted memory card.