PURPOSE: To improve dependability by radiating number codes stored in an IC as high frequency signals by excited energy obtained from a solar battery and reading the high frequency signals.

CONSTITUTION: Optical energy irradiated from a light emitting source 2 radiates a solar battery SB of a card 1 and generates a DC voltage EB at an output terminal. The voltage EB thus generated is impressed as a bias voltage of an ROM, a number code generation circuit NUG, parallel-serial information conversion circuit S/P and an oscillating OS of high frequency. When the voltage EB becomes higher than a fixed value, serial digital signals are generated from the circuit S/P and modulates the oscillation OS, and high frequency electromagnetic field is radiated from an antenna AT. This electromagnetic field is detected by an antenna 3 and inputted into a receiver 4. The receiver 4 demodulates signals, which cause a CPU3 to output a number code CD from the signals. The device requires no complex mechanical operation part, thereby causing few troubles to improve dependability.