A multi-card cellular telephone apparatus includes a central processing unit and a plurality of SIM cards connected to the central processing unit through slots. The active elements in the other connection configuration have the identical or similar structure to the active element in the first connection configuration, and are connected to power lines of an internal circuit associated therewith but not connected to signal wires and so on in the internal circuit. The cross sectional area of the reduced cross sectional area is less than the cross sectional area of each of the first and second main body regions. Still another feature is that a magnetic hat concept can be applied to a variety of magnetic core shapes.