The invention concerns a gas burner (1) with multiple concentric flame rings, comprising: a central burner (2) with a central ring of flame orifices (5), and axial central gas injector (6) and convergent-divergent means (7) forming venturi; and an annular outer burner (3) coaxially surrounding the central burner and provided with at least one annular ring of flame orifices (9), gas injecting means (10) and convergent-divergent means (12) forming venturis; the gas injecting means (10) include several radial gas injectors (11) around the central injector (6); the convergent-divergent means (12) include several radial convergent-divergent conduits (13) forming tubular venturis coaxial respectively to the radial injectors (11) and emerging in the annular outer burner.