<p>PURPOSE: A mast windmill is provided to lower power generation costs with easy maintenance and to enable wind power generation with a simple structure. CONSTITUTION: A mast windmill comprises a rotary plate(10), a rotary shaft(20), and a shaft support beam(40). The rotary plate includes a predetermined area and is radially installed in the rotary shaft. The rotary shaft is installed by being horizontally put down on the upper part of rotary space(30). The shaft support beam is installed by crossing the upper part of the rotary space, and the rotary shaft is installed in order to be horizontally rotated. [Reference numerals] (AA) Wind; (BB,CC) Meadow</p>
