PURPOSE: To provide a connecting device and an information processor in an information processing system in which plural peripheral devices can be simultaneously connected to one of the connecting parts of the information processor.

CONSTITUTION: This information processing system is constituted by connecting the first connecting part 4 of the connecting device 5 to the connecting part 3 of the information processor 1 and connecting the plural peripheral devices 11a, 11b, 11c to the plural second connecting parts 9a, 9b, 9c of the connecting device 5, and the connecting device 5 is constituted so as to be provided with an information rewriting part 7 which rearranges the information of the function information storage parts 12a, 12b, 12c of all the connected peripheral devices 11a, 11b, 11c and writes it in an undermentioned integrated information storage part 6, the integrated information storage part 6 which manages the peripheral devices 11a, 11b, 11c systematically on the basis of the stored function information, and a peripheral device selecting part 8 which selects one of the connected peripheral device 11a, 11b, 11c when the information processor 1 accesses it.