To improve the mixing quality of a gas/air mixture with a fixed pressurization of a gas.

This burner mainly comprises a spiral flow generator for the flow of combustion air and a means to inject at least one kind of fuel into the combustion air flow. Moreover, a mixing zone is arranged on the downstream side of the spiral flow generator. The mixing zone has a certain plurality of transfer paths inside a first mixing zone part in the direction of fluidization and the transfer paths are so arranged as to transfer a flow produced in the spiral flow generator to a mixing pipe installed after it on the downstream side of the transfer paths. A heat generator thus arranged is operated. In this case, a combustion air flow 115 flowing into the spiral flow generator runs along a turbulence generator 300, which is positioned on the upstream side of a part where a fuel is injected 116 into the combustion air flow 115.