Provided is a molten metal holding furnace with heat dissipation and insulating properties. An insertion hole 20 of a molten metal holding furnace 10 has an inside cylindrical portion (tapered surface) 21 and an outside cylindrical portion 22 (cylindrical surface). A heating tube 30 has a distal cylindrical portion 35 corresponding to the inside cylindrical portion 21 and a proximal cylindrical portion 36 corresponding to the outside cylindrical portion 22. The heating tube 30 is inserted and positioned in the insertion hole with the distal cylindrical portion 35 positioned at the inner cylindrical portion 21 and the proximal cylindrical portion 36 positioned at the outside cylindrical portion 22. A filling material 60 is filled between the heating tube 30 and the insertion hole 20.