To improve durability of the furnace cover for an electric furnace to prolong the life.

A heat resisting and corrosion resistant zirconia-based ceramics thermal spraying layer B is formed through a cermet thermal spraying layer A absorbing thermal expansion, at least at the inside face of a water tube panel 2 in which a cooling water passage is formed in the furnace cover body 1. Further, a spark-resistant aluminium oxide-based ceramic thermal spraying layer C having a high insulation property is formed on the zirconia based ceramics thermal spraying layer B of the inside face of the water tube panel 2 in the vicinity of an electrode.