To orderly store more cards without buing a new purse for replacing an existing purse, and without considerably increasing thickness of the existing purse.

Card pockets 4 are arranged in a row on a front and a back faces of a rectangular card storing part 2. A rectangular card inserting part 3 is arranged on one side edge of the card storing part 2. The card pocket extension member is easily fitted inside the purse 8 by inserting the inserting part 3 to an existing pocket part 2 of the purse 8. Each of the card pockets 4 makes it possible to increase the number of cards to be stored without buying a purse for replacing the existing one 8.