To perform an application to the surface of an object and molding into complicated shapes and provide a heat insulating material obtained after drying with heat insulation which is excellent for a high temperature use, by including ceramic fiber filling and gel colloid of specified weight in a heat insulating material, providing gel colloid with viscosity of a specified value or more and forming the gel colloid from colloid of inorganic oxide.

Heat insulating blend is a ceramic fiber heat insulating material blend formed from gel colloid and at least substantial ceramic fiber filler. The heat insulating blend contains ceramic fiber filler of about 10 to 40 wt.% and gel colloid of about 60 to 90 wt.%, and the gel colloid has viscosity of about 5,000 centipoise or more and is formed from water suspension of inorganic oxide. Blend or gel in which filler is added to the gel colloid can be quickly applied to a substrate. The blend or gel can be molded into various kinds of shapes by a pouring type, pressing molding or other methods, and when the blend is dried after the application, a product can be obtained.