To provide an heat insulation method for a holding vessel for a high temperature melt where heat dissipation caused by radiation can be effectively reduced, further, the method can be performed at a low cost, and the repair or the like of a heat insulation means can be correctly and easily performed as well.

The external face of a holding vessel for a high temperature melt is coated with a heat resistant coating material, thus a coating film with a low emissivity, preferably with an emissivity of 0.6 is formed. Heat dissipation caused by radiation from the vessel is effectively reduced, and further, what is necessary is just to apply a heat resistant coating material to the eternal face of the vessel, thus it can be performed at a low cost, and also, maintenance is facilitated.