An electric power supply system, to which the electric field coupling electric power transmission technology is applied, includes an electric power transmission electrode for transmitting electric power from an electric power source, an electric power reception electrode that is disposed so as to contactlessly face the electric power transmission electrode to form a junction capacitance, and receives the electric power transmitted from the electric power transmission electrode through the junction capacitance, and a plasma generation unit for generating a plasma in a space between the electric power transmission electrode and the electric power reception electrode in which the junction capacitance is formed.