<p>A Savonius windmill (1) allowing an increase in rotating efficiency, comprising a rotating member (10) having a transmission shaft (3) and a connection member (8) and rotating around a specified rotating axis and a plurality of blades (5) connected to the rotating shaft (10) and rotated by wind applied to the wind receiving surfaces (5a) of the blades. The plurality of blades (5) guide the wind applied to the wind receiving surface (5a) of each of the blades (5) to the wind receiving surfaces (5a) of the other blades (5), and the area of the wind receiving surface (5a) of each of the blades is larger in areas apart from the rotating axis of the rotating member (10) than those near the rotating axis.</p>
