<p>PURPOSE: A wind turbine is provided to improve rotary force by improving the structure of a blade. CONSTITUTION: A wind turbine contains: a rotating device(10) composed of a rotation unit(11) connected to a structure(1) and a support structure(12) coupled to the rotation unit; many blades(20) coupled to the rotating device and composed of a first round coupled to an outer reinforcement(12b) of the support structure, a second round formed to have the larger radius of curvature than the first round, and a streamlined sail unit connecting the first round and the second round; a power transmission device(E) like a gear or a belt pulley connected to the rotting device rotating by the blade; and accessory equipment like an accelerator and a generator.</p>
