Provided is a small-sized propeller windmill which can efficiently generate power even when a wing speed is low, has no possibility that the windmill is broken even when a strong wind blows, can stably ensure a weathercock direction of a base blade, and can suppress an environmental burden, in such a propeller windmill, the blade having a corrugated wing shape is supported in a cantilever manner by way of an elastic body, and the blade and the elastic body are made of paper or plastic. Further, to stably ensure the weathercock. direction of the base blade, a weathercock stabilizing mechanism is arranged behind the base blade.