Abstract: A flame photometric detector analyzer comprises a first conduit through which a fuel gas flows, a fuel gas nozzle connected to the first conduit to be supplied with the fuel gas to form a flame at the tip thereof, a second conduit through which a combustion supporting gas is supplied to the vicinity of the tip of the fuel gas nozzle to assist the combustion of the fuel gas discharged from the nozzle, a third conduit through which a sample gas having a measuring object component is supplied to the flame, a device for controlling the concentration of oxygen contained in the combustion supporting gas to be supplied to the flame within a range from 11.5 to 16%, and a device responsive to photoemission from the measuring object component of the sample gas introduced into the flame, thereby decreasing the effect of interference substances to obtain high accuracy of measurement even though the measuring object is of considerably low concentration.