To provide a mechanism to automatically minimize all wing elevation angles so as to able to keep the safe operation by escaping the excessive wind pressure applied on a wing in the case of strong wind, because special methods such as an operation stopping, etc., are required in a windmill to prevent the breakage owing to the overrunning, etc., in the case of strong wind.

In a wind elevation angle changing device of a lift force vertical shaft windmill, a wing axis (5) is axially supported in a plurality of wing axis retainers (3) of a wing support arms (2) installed on a main shaft (1), a crank arm (6) having a crank pin (7) is secured to the wing axis (5), an elastic body (9) is stretched between a hunger (8) and the crank pin (7) of the wing support arm (2), and the elevation angle of the wing (4) is controlled only by the elastic force. Thereby, the wing (4) can be also controlled in elevation angle for the rotation range of 360 degrees in the reverse direction to the rotation direction of the main shaft as the main shaft (1) rotates 360 degrees in the case of strong wind, safe operation can be realized by escaping as streaming the excessive wind pressure such as a vertical tail fin of an aircraft. As illustrated in Fig. 6, the technology to control the wing elevation angle by the elastic force via an interlocking mechanism also belongs to the means to solve the problem.