A fuel injection apparatus for separately ignited internal combustion gas engines is proposed. The fuel injection apparatus comprises an air intake stack in which an injection valve is arranged upstream of a throttle valve. A ring slot developed approximately Venturi-shaped is formed between the casing of the injection valve and the cylindrical inner wall of the air intake stack. An air bypass line discharges into the narrowest cross-section of the ring slot developed approximately Venturi-shaped which begins upstream of the approximately Venturi-shaped ring slot. An air measuring organ with at least one temperature dependent resistance for measuring the air mass flowing through is arranged in the air bypass line. Downstream of the temperature dependent resistance the air bypass line has a section developed in the shape of a funnel into which a cone shaped brake body concentrically protrudes which is supported axially displaceable and through which not only an optimal output signal of the air measuring organ in dependence on the sucked in air mass can be adjusted, but a balancing of the characteristic curve of the air measuring organ can take place as well. The proposed fuel injection apparatus allows a compact construction which permits the accommodation in the engine room of the internal combustion engine of motor vehicles even with cramped conditions as well as a reliable method of operation.