A combustion device includes a combustion chamber having an exhaust gas opening. The combustion chamber has a first region having a plurality of circular-segment-shaped cross-sections, which are parallel to each other and each have a circle centre point. A connection of the circle centre points lies substantially on an axis. A gas supply line is connected to the combustion chamber in such a way that a discharge point is formed, that the combustion chamber has a mixing region in the region of the discharge point for mixing gas supplied via the gas supply line with gas rotating in the combustion chamber, and that the discharge point is arranged on a bottom side of the combustion chamber in an operating position, wherein gas supplied via the gas supply line flows against the first region tangentially from below.