In the related art, there is known an electronic apparatus (such as a mobile phone terminal) where a card unit (such as a SIM card) obtained by installing various devices on a substrate can be mounted. Such an electronic apparatus is driven by electric power from a battery. In addition, the electric power from the battery is also supplied to the card unit mounted on the electronic apparatus.
However, there is a problem in that it is difficult to drive the devices installed in the card unit when an electric power supply capability of the battery becomes lower than a predetermined value (for example, when a remaining battery level is lower than a predetermined value and the like).