There is a need, in lightning protection equipment for a windmill, for maintenance to be made easier while a high level of safety is also maintained. In the present invention, a lightning current received by a receptor on a blade is guided to a grounding wire within the blade. The grounding wire passes through a space on an inner peripheral side of a bearing for altering the pitch angle of the blade, and is guided into a rotor head. The lightning current can be guided toward the rotor head without using the bearing as a path and without the use of a brush or other sliding/abrasive member.