5. The wind turbine generating apparatus according to
claim 1, wherein the air flow forming means includes:
an air flow path forming member attached to the inside of the rotor head, separating the communication path to an inner peripheral side and an outer peripheral side, separating an internal space of the rotor head to a hub outer peripheral face side and a rotor head inner wall face side, and having an opening for allowing the hub outer peripheral face side and the rotor head inner wall face side to communicate with each other;
inner-peripheral-side air circulation guides fixed to the rotor head side and arranged over an entire circumference along the inner peripheral side of the communication path; and
outer-peripheral-side air circulation guides fixed to the nacelle side and arranged over an entire circumference along the outer peripheral side of the communication path, wherein
air in the nacelle is introduced into the air flow path forming member and circulated therein.