This invention is to provide an ultra-miniaturized, thin-sized memory card provided with a mechanism for preventing a wrong insertion to a memory card slot. A multi-function memory card is composed of a card body and a cap for housing the card body. The card body is made of mold resin that encapsulates plural semiconductor chips mounted on a main surface of a wiring substrate. The card body is housed into the cap with the back face of the wiring substrate facing outward. Guide channels are provided at both side faces of the cap for preventing that the card is inserted upside down. Further, a convex section is provided at the trailing edge of the cap for preventing that the card is inserted in the wrong direction.