To provide a wind-power generation device capable of efficiently generating electric power and significantly reducing noise generated when a blade rotates.

A wind-power generation device 1 which can generate electric power by converting wind power into the electric power comprises: blades (a small-diameter blade 2a and a large-diameter blade 3) which can rotate about a shaft member L by catching wind; and power generation means 4 which has a rotor 4a rotating together with the shaft member L and a stator 4b fixed with the rotor 4a arranged opposite thereto and generates electric power through relative rotation between the rotor 4a and the stator 4b on the basis of the rotations of the small-diameter blade 2a and the large-diameter blade 3. The wind-power generation device 1 also has magnetic force support means 5 which can rotatably support the shaft member L and the blades by magnetically levitating the shaft member L.