Provided is an auxiliary burner for an electric furnace capable of increasing and homogenizing the heating effect of iron scrap by suitably and efficiently burning solid fuel along with gas fuel. This auxiliary burner 100 for an electric furnace comprises a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 in the stated order from the center side, all arranged coaxially, and is characterized in that: a flow path 30 of the combustion-supporting gas injection tube 3 is provided with a plurality of swirl vanes 4 for swirling the combustion-supporting gas, and a flow path 20 of the gas fuel injection tube 2 is provided with a plurality of swirl vanes 5 for swirling the gas fuel; and the angle θ1 of the swirl vanes 4 and the θ2 of the swirl vanes 5 satisfy the relationship θ1