Provided is an arc furnace, including: a furnace body having a bottomed cylindrical shape; a furnace lid that openably closes an opening of the furnace body; an electrode that is provided at the furnace lid and melts a metal material supplied into the furnace body by electric discharge; a tilting floor that is tiltable within a plane substantially perpendicular to the tilting floor; and a rotation mechanism that is provided on the tilting floor inward from an outer circumference of the furnace body to support a bottom wall of the furnace body, and rotates the furnace body around a cylinder axis thereof.