Disclosed herein is a wind turbine. The wind turbine includes a support unit having a lower base block and a cylindrical protruding part. A rotary cylinder is rotatably supported by the protruding part. A rotating shaft extends from a center of the rotary cylinder to rotate along therewith. An upper bearing is installed on the protruding part to support the rotary cylinder. A lower bearing is installed on the lower base block to support the rotary cylinder. A plurality of vanes is installed along the outer circumference of the rotary cylinder at regular angular intervals, and is opened outwards relative to the rotary cylinder or closed to be in close contact with the outer circumference of the rotary cylinder, according to a position relative to a wind direction. An angle limiting means prevents each vane from being opened beyond a preset angle.
