Expanding apparatus for portable electronic apparatus

An expanding apparatus includes a container (22) containing expansion boards for expanding the functions of an electronic apparatus. The container has a supporter (24) on which the rear portion of the electronic apparatus is mounted. The supporter has a fitting groove (32) to which a stand of the electronic apparatus mounted on the supporter is fitted, so that the apparatus is positioned with respect to the container. A slide connector (40) is attached to the container to be movable to a connecting position where the connector is connected to a connector of the positioned electronic apparatus.