To provide a wind power generation unit having a capability to capture wind energy effectively and withstand strong wind.

A wind power generation unit has a rotational axis 12 ] approximately horizontally in a manner to follow a wind direction. On the periphery of the rotational axis 12 rotor blades 13 in a spiral shape are provided. On the periphery of the rotor blades 13 an outer tube 14 having a tubular shape with opened ends and coaxial with the rotational axis 12 is provided. On the windward side of the outer tube 14 collectors 15 having a mechanism to open and close are provided and on the leeward side a generator 11 mechanically connected to the rotational axis 12 is provided. The collectors 15 are supported by a frame mounted on the windward side. Depending on wind speed the collectors 15 can be operated by a motor 29 and a closing mechanism 24 so that the collectors 15 can open in a flare shape to collect wind streams or close to a cone shape to shut off the wind streams.