There is provided a spar-type floating offshore wind power generation facility that suppresses a reduction in power generation efficiency caused by tilting of a tower, suppresses rotational motion (yaw motion) around a vertical axis, prevents a ship from coming into contact with a mooring cable, and, at the same time, appropriately holds the tilted posture state of the tower. A floating offshore wind power generation facility 1 includes a floating body 2, a mooring cable 3, a tower 4, and a windmill 5 installed at the top of the tower 4, the windmill 5 including a nacelle 6 and a plurality of blades 7. The rotation axis of the windmill 5 has a predetermined upward angle to avoid contact between the blades 7 and the tower 4, and the windmill 5 is of a downwind type in which the blades 7 are attached to the leeward side of the nacelle 6 and installed with the back surfaces of the blades 7 facing windward, and the mooring point of the mooring cable 3 to the floating body 2 is set at a position below the surface
