An air-gas mixture burning appliance , comprising: a burning unit for burning a combustible air-gas mixture , an air-gas mixing unit that is arranged upstream of the burning unit and comprises a predetermined plurality of air-gas mixers for mixing of air and gas to form the combustible air-gas mixture , and a gas supply unit that is arranged upstream of the air-gas mixing unit , the gas supply unit comprising: a first gas flow channel , a plurality of second gas flow channels that is arranged between the first gas flow channel and the predetermined plurality of air-gas mixers , and a gas flow distance regulating device that is arranged between the first gas flow channel and the plurality of second gas flow channels , the gas flow distance regulating device being adapted to regulating a flow distance of the gas from the first gas flow channel to the plurality of second gas flow channels in order to adjust an arrival time of the gas at the predetermined plurality of air-gas mixers and comprising a baffle plate that extends in longitudinal direction from a center towards two ends and that is adapted to route the gas from the first gas flow channel to at least one of the plurality of second gas flow channels . a burning unit for burning a combustible air-gas mixture , an air-gas mixing unit that is arranged upstream of the burning unit and comprises a predetermined plurality of air-gas mixers for mixing of air and gas to form the combustible air-gas mixture , and a gas supply unit that is arranged upstream of the air-gas mixing unit , the gas supply unit comprising: a first gas flow channel , a plurality of second gas flow channels that is arranged between the first gas flow channel and the predetermined plurality of air-gas mixers , and a gas flow distance regulating device that is arranged between the first gas flow channel and the plurality of second gas flow channels , the gas flow distance regulating device being adapted to regulating a flow distance of the gas from the first gas flow channel to the plurality of second gas flow channels in order to adjust an arrival time of the gas at the predetermined plurality of air-gas mixers and comprising a baffle plate that extends in longitudinal direction from a center towards two ends and that is adapted to route the gas from the first gas flow channel to at least one of the plurality of second gas flow channels . a first gas flow channel , a plurality of second gas flow channels that is arranged between the first gas flow channel and the predetermined plurality of air-gas mixers , and a gas flow distance regulating device that is arranged between the first gas flow channel and the plurality of second gas flow channels , the gas flow distance regulating device being adapted to regulating a flow distance of the gas from the first gas flow channel to the plurality of second gas flow channels in order to adjust an arrival time of the gas at the predetermined plurality of air-gas mixers and comprising a baffle plate that extends in longitudinal direction from a center towards two ends and that is adapted to route the gas from the first gas flow channel to at least one of the plurality of second gas flow channels . <EOS>