This patent application relates to a burner which includes a burner head in the shape of a sleeve, under the burner head is connected with a ring gas-separating box, and in the space between the burner head and the gas-separating box there is a cylinder mixing box to mix the air and gas. Said gas-separating box has a independent center hole to bring in the air and gas inlets to bring in the gas. Several notches which are equispaced with each other and slant upwardly are set on the cylinder surface of the mixing box, while on the surface of the notches are positioned connecting holes to let the air out. Such a structure promotes the mixing process more fully of the dispersed gas and air in the slant upward notches, and the mixed flow rotates upwardly to reach the flame hole as a inversed cone frustum. Due to the full mixing of the gas and air and upward rotation of the mixed flow, the flame will burn more completely and be uneasy to be extinguished.