By means of a simple structure, lightning resistance is improved without increasing the level of fluid noise due to a lightning discharge member provided on a surface of a wind turbine blade. A wind turbine rotor blade lightning discharger, in which a diverter strip serving as a lightning discharge member protrudes from a surface of a wind turbine blade that extends in a radial direction from a rotor head supported in a freely rotatable manner, includes a noise suppressing structure that suppresses the generation of a Karman vortex, which causes noise, on the downstream side of the diverter strip with respect to an airflow that flows at the surface of the wind turbine blade during rotation of the wind turbine rotor blade.