To provide an aircraft which easily estimates wind direction using information acquirable in normal flight, determines approach direction based on the estimated wind direction, and can realize "perfect automatic approach flight", and a wind direction estimating method capable of easily estimating wind direction using the aircraft.

The aircraft 10 comprises an ADS 50 for detecting air speed, a GPS 60 for detecting air speed, a magnetic direction sensor 70 for detecting the azimuth angle, a speed difference calculating means 81 for calculating difference (speed difference) between the airspeed and ground speed, a wind direction estimating means 82 for estimating the wind direction based on the azimuth angle and the speed difference, and a guiding means 83 for controlling a steering device 30 to make the own aircraft approach a predetermined target landing region from the lee side based on the estimated wind direction.