To provide miniaturized electronic equipment which is functioned by providing power from radio waves from the outside, without radiation of strong radio waves for supplying power to the relevant miniaturized electronic equipment and without work for making the relevant miniaturized electronic equipment close to a prescribed external antenna by taking out the equipment each time.

The radio wave of 800 MHz band from a portable telephone terminal 2 is received by an antenna part A to be resonated on the 800 MHz band inside the miniaturized electronic equipment (namely a radio ID card 1) and this is rectified by a diode 13. A high frequency component is removed by a pass capacitor 14, a secondary battery 15 (which can receive power even with an external power source) is charged with this radio wave and a function circuit 16 is operated by this secondary battery 15.