An electronic device having at least a loop-shaped electric conductor generating electric power by electromagnetic induction is provided. The electronic device includes a voltage-detecting unit, a voltage-comparing unit and a separating unit. The voltage-detecting unit is configured to detect a voltage generated in the electric conductor by the electromagnetic induction. The voltage-comparing unit is configured to make a comparison between the voltage detected by the voltage-detecting unit and a predetermined reference voltage and determining whether the voltage detected by the voltage-detecting unit exceeds the predetermined reference voltage. The separating unit is configured to break an electric connection between the electronic conductor and an electronic circuit connecting to the electric conductor when the voltage-comparing unit determines that the voltage detected by the voltage-detecting unit exceeds the predetermined reference voltage.