PURPOSE: To enable improvement in dimensional stability of a mold material for dental use by lessening penetration of phosphorous into the surface of mold to thin a reaction layer, preventing weakening of titanium, reducing surface roughness of the mold in a phosphate-based mold material for dental use.

CONSTITUTION: In a mold material for dental use comprising a refractory, a phosphate, a metal oxide and a colloidal silica sol, ammonium primary phosphate is used as the phosphate, the amount of the phosphate blended is set 3-5wt.% the whole mixture excluding the colloidal silica sol and colloidal silica having ≥40μm particle diameter is used as the colloidal silica.