A method for adjusting flow velocity of reaction gas and dispersion air of pulverous solid material when feeding reaction gas and finely divided solids to a reaction shaft of a suspension smelting furnace for creating a controlled and adjustable suspension, where reaction gas is fed into the furnace from around a finely divided solid material flow, said solids being distributed with an orientation towards the reaction gas by means of dispersion air, wherein the flow velocity and discharge direction of the reaction gas to the reaction shaft are adjusted steplessly by means of a specially shaped adjusting member moving vertically in a reaction gas channel and by means of a specially shaped cooling block surrounding the reaction gas channel and located on an arch of the reaction shaft, so that the velocity of the reaction gas is adjusted to be suitable, irrespective of the gas quantity, in a discharge orifice located at a bottom edge of the reaction shaft arch, from which orifice the gas is discharged into the reaction shaft and forms there a suspension with the pulverous solid material, and the dispersion air needed for dispersing said material is adjusted according to the supply of the pulverous solid material, wherein the adjusting member adjusting the cross-sectional area and orientation of the reaction gas flow is cooled, and wherein curved surfaces of the adjusting member and of the cooling block located on the side of the reaction gas channel are designed so as to reduce the cross-sectional flow area in the discharge direction of the reaction gas.