PURPOSE: To provide a premixing burner applicable additionally to an existing premixing combustion chamber in which a uniform velocity distribution can be attained in a mixing zone simultaneously with intimate mixing of combustion air and fuel in an extremely short section and back fire can be avoided without requiring any mechanical flame holder.

CONSTITUTION: In a premixing burner comprising a pilot burner 101 disposed in the center and a plurality of main burners 52 arranged around the pilot burner 101, a gaseous and/or liquid fuel is injected into the main burner 52 having a circular duct 20 as a secondary flow into a gaseous main flow. The main flow is guided over vortex generators 9, a plurality of which are arranged next to one another around the circumference of the duct 20 through which flow takes place.