PURPOSE: To prevent propeller materials of stainless steel, brass, iron, aluminum or the like from metallic corrosion caused by static electricity by mounting an earth electrode of a stainless steel wire widened radially on the tip.

CONSTITUTION: A discharging wire radially widened by loosening the tip of a stainless steel wire 1 is crimp connected to a DV electric wire 2 together with a shield 2a and core wire 2b of the DV electric wire 2 with a sleeve 12 to prevent the electric wire from rust by a calking agent. Only the core wire 2b is fitted by a crimp terminal 11 to an apparatus fixing bolt or bolt and nut inside the metallic part projecting to an outer plate part like an engine frame mounting bolt, flange mounting bolt of a kingston, propeller shaft carrier fixing bolt, cock bolt of the propeller and cock bolt of a ludder.