The invention provides a wind-power generation device that can blow wind at a sufficient speed to a windmill through a vertically extending wind tunnel tube, and can generate a sufficient amount of power. The wind-power generation device (10) is provided with: a tubular wind tunnel tube (30) closed at the bottom end, the tube (30) having a wind blow-out port (32) provided at the top end and a plurality of openings provided throughout the length and breadth of the entire peripheral wall; a plurality of opening-closing windows (52) that open the openings when receiving wind from the outside of the wind tunnel tube (30), and close the openings when receiving wind from the inside of the wind tunnel tube (30); a windmill (60) arranged facing the blow-out port (32) in the top side of the wind tunnel tube (30); and a power generator that generates power by means of the rotation of the windmill (60).