A mobile device includes a driving circuit, a first accommodation section configured to accommodate a first battery which supplies electric power to the driving circuit and which is an all-solid-state battery having a solid electrolyte, a control circuit configured to control the driving circuit such that driving is performed in one of a plurality of modes including a first mode and a second mode in which power consumption is smaller than the first mode, and a determination circuit configured to determine whether electric power is supplied from an external power source to the first battery. When the determination circuit determines that the electric power is supplied from the external power source to the first battery, the control circuit performs switching from the second mode to the first mode.