To secure the stable contact of electrodes even when a portable terminal device falls or vibrations are applied to the terminal device, further to prevent the deformation of the electrodes even when large impact is given to the terminal device due to fall, etc., and to prevent power disconnection and transmission disconnection with a simple battery structure and a battery chamber constructed in the form of simple molding.

This portable terminal device primarily comprising the battery chamber formed in a housing and a cover for covering the battery chamber is provided with a terminal constructed so as to be able to be electrically connected to an electrode of a battery at one end of the battery chamber, elastomer on a side facing the terminal constructed so as to be able to be electrically connected to the electrode of the battery in the battery chamber, and a 1st engaging part for engaging with the battery on the bottom face of the battery chamber. When a battery having a 2nd engaging part that is engaged with the 1st engaging part is mounted in the battery chamber, the elastomer gives the battery force to move toward the terminal for the electrode.