To provide a mounting structure of an air fan for a range hood fan which is mountable on a range hood fan body manufactured by the use of a color steel sheet without causing any vibration sound called chatter sound.

An air fan B is screwed to a leg 7 by anchoring the air fan with a screw to the leg 7 provided at a location that is a position where the air fan B is anchored with a screw to prevent any vibration due to driving force of the air fan B from happening. Molding of the leg 7 by press molding ensures manufacture of a range hood fan body A' and a fan casing b1 employing a color steel sheet.