PURPOSE: To eliminate poor detection of stripes of magnetic cards, by installing a specified backup to prevent poor contact between magnetic cards and the magnetic head.

CONSTITUTION: When a card 1 is pressed against a space between a magnetic head 2 and a backup roller 3A which is pressed against the head 2, the roller 3A is pushed down and the card 1 is inserted into the space. Then, the head 2 detects stripes of the card 1, and the card is fed to the next processing course by means of a carrying belt 4 and the roller 3A which are rotated. Since the diameter of the roller 3A is gradually reduced from the central periphery 7 toward marginal peripheries 6 at both sides, that is, the periphery of the roller has an arced surface, the card 1 can contact with the magnetic head 2 with a degree of freedom because the right and left sides of the lower surface are free against the head 2, and thus, poor contact between the magnetic card 1 and the magnetic head is eliminated.