PURPOSE: To obtain a lightweight product excellent in refractoriness and heat insulation without requiring burning and processing (cutting) by blending a specified ratio of a light-weight aggregate, a refractory plastic clay and a binder, press-molding the resultant mixture and drying it.

CONSTITUTION: This refractory and heat-insulating material is obtained by blending 10 to 50wt.% 1ightweight aggregate, 50 to 90wt.% refractory plastic clay and 0.1 to 10wt.% binder, press-molding the resultant mixture into an arbitrary shape and drying it without burning it. As the lightweight aggregate, e.g. diatomaceous earth, pearlite, expanded vermiculite and porous granular chamotte are exemplified. As the refractory plastic clay, e.g. kibushi clay, kaolin clay and bentonite are exemplified. As the inorganic binder, e.g. water glass, portland cement and a phosphoric acid salt are exemplified. As the organic binder, e.g. methyl cellulose, lignin sulfonate, a phenol resin and an epoxy resin are exemplified.