In the field of portable electronic devices in the future, portable
electronic devices will be desired, which are smaller and more
lightweight and can be used for a long time period by one-time charging,
as apparent from provision of one-segment partial reception service
"1-seg" of terrestrial digital broadcasting that covers the mobile
objects such as a cellular phone. Therefore, the need for a power storage
device is increased, which is small and lightweight and capable of being
charged without receiving power from commercial power. The power storage
device includes an antenna for receiving an electromagnetic wave, a
capacitor for storing power, and a circuit for controlling store and
supply of the power. When the antenna, the capacitor, and the control
circuit are integrally formed and thinned, a structural body formed of
ceramics or the like is partially used. A circuit for storing power of an
electromagnetic wave received at the antenna in a capacitor and a control
circuit for arbitrarily discharging the stored power are provided,
whereby lifetime of the power storage device can be extended.