To provide a wind power generation device for reducing limitation of an installation place more than a propeller system, capable of expecting power generation of efficient larger output than a Savonius type, relatively easy in adjusting power generation output in a weak wind and a strong wind, and capable of adding both the function capable of generating electric power even at windless time and the function such as an advertisement tower.

This wind power generation device has an impeller 2 having a rotary shaft existing in the horizontal direction, a support frame 3 of this impeller, a rotary support mechanism part 4 capable of rotating this frame in the horizontal direction, and a support foundation part 5; and is provided with a windbreaking member 6 capable of preventing wind on a lower directional half of the impeller 2 on the windward side of the support frame 3 and a vertical tail 7 on the leeward side; and uses a windmill in the form of arranging a wind introducing member 8 capable of guiding the wind from below into the rotational direction of the impeller 2 to a lower rear part of the windbreaking member 6. A lower part of the wind introducing member 8 can be rotated. A wind guiding quantity can be adjusted. Torque of the impeller can be adjusted in a weak wind and a strong wind. A light receiving part 11 of a solar battery is attached to an upper outside surface of the support frame 3. The function of photovoltaic power generation and the function of the advertisement tower are added by arranging the light receiving part 11 of a solar battery on the upper outer surface of the support frame 3 etc. applying a character to the vertical tail 7.