A high-lift device suppresses the occurrence of aerodynamic noise while minimizing an increase in airframe weight. The device includes a slat main body disposed to be able to extend from and retract into a main wing, and a concave part formed on the slat main body at a location facing the main wing and able to accommodate at least a part of a leading edge of the main wing. The device also includes an airflow control part disposed at an area in the concave part facing an upper surface of the main wing, that is accommodated between the main wing and the concave part when the slat main body is retracted into the main wing, and that suppresses turbulence colliding against the area in the concave part facing the upper surface of the main wing when the slat main body is extended from the main wing.