There is disclosed a battery pack, which has a plate-shaped resin-formed body to divide an internal space of the battery pack into at least two spaces in a thickness direction thereof, so that a battery is received in a first internal space, while a wiring substrate having a control circuit packaged thereon is placed in a second internal space, thereby allowing the battery pack to hold an input/output circuit or the like of a memory card securely in a limited space in the battery pack, while ensuring that a sufficient insulation is provided to the battery, when the battery pack is used for PDA'S, for instance.