A micro gas burner is provided that generates a stable, pre-mixed flame that produces little to no soot or unburned hydrocarbons. The gas burner includes a fuel inlet, nozzle, oxygenation chamber with at least one air inlet, a mixing chamber having a frustoconical inner wall, at least one permeable barrier and a flame holder. The gas burner thoroughly mixes fuel and entrained air to form a nearly stoichiometric mixture prior to combustion. The gas burner mixes the fuel and air so thoroughly that it requires a lower fuel flow rate than would otherwise be necessary to produce a stable, pre-mixed flame. The gas burner may include an optional flame tube with an optional exhaust port in which a flame is contained and sequestered from diffusing air.