To prolong the lifetime of a bottom electrode of furnace by stabilizing the operation thereof.

An anode electrode section 14 comprising a rod-like electrode 18, irregular refractories 21 surrounding the electrode 18, and sleeve bricks 23 fitted vertically between the electrode 18 and the refractories 21 through a horizontal joint 22 at least across two stages is buried in the bottom 10 of a DC electric furnace to obtain a sleeve brick structure for the bottom electrode of DC electric furnace. Reinforcing sleeve bricks 24 are placed between the sleeve bricks 23 and the refractories 21 and the outer circumferential surface of the sleeve brick 23 is jointed through a bonding material to the inner circumferential surface of the sleeve brick 24.