To provide a range hood and its adjustment method having high collection efficiency even under disturbance wind (cross wind).

This range hood disposed at an upper part of a heating cooker comprises a suction opening opposed to the heating cooker for sucking the air, a discharge opening formed at an outer side of the suction opening and forming air curtains at an outer side at least in two directions observed from the suction opening, by discharging the air downward, and a control means for controlling relative strengths of the air curtains in two directions.