To provide a card reader/writer having a rational stock means for receiving a card.

The stock means 400 includes a storage unit 410 having a space for stacking a card 10 above a carrying path 110; a biasing means 420 which biases the card received in the storage unit toward the carrying path; and a cam mechanism 430 which pushes up the card from the carrying path toward the inside of the storage unit. The cam mechanism includes a plurality of cam bodies 431, 432 each of which rotates about an axis parallel to the carrying direction of the card to push up the whole body of the card by the plurality of cam bodies. At least some of the plurality of cam bodies includes an eccentric recess 430a. When the card is pushed up, the eccentric recess is located below the pushed-up card, and the other card is carried by a carrying means and fitted into the eccentric recess, whereby the pushed-up card overlaps the other card.