PURPOSE: To simplify and miniaturize the card reader device by detecting the notched parts of identification(ID) codes formed on the peripheral edge of a card by a detecting means.

CONSTITUTION: The device is provided with a guiding member 15 for guiding the card 1 to a fixed position at the time of inserting the card 1 and plural detecting means 16 respectively detecting the existence of notched parts 1c of the card 1 inserted to the fixed position and ID codes are read out based upon the detecting results of the means 16. The detecting means 16 can be constituted of mechanical switching mechanisms or photosensors for detecting the existence of e.g. notched parts 1c. Consequently, the constitution of the device can be simplified and miniaturized.