PURPOSE: To destroy and to remove detrimental substances through combustion easily, and to obtain economically a solid fuel for fuel of agriculture in house, by blending combustible wastes of agriculture decomposing at high temperature with a synthetic resin containing neither Cl nor F, followed by molding.

CONSTITUTION: Combustible waste of agriculture, e.g., rice hulls, straw, etc. are ground by rubbing each other preferably at 150W200°C, substances on the surface detrimental to combustion are destroyed, and the waste is blended with a synthetic resin containing neither Cl nor F consisting of a thermoplastic resin waste, preferably foamed poly styrene by coating, etc. The blend is molded into a given shape to give the desired solid fuel. Preferably about 3W5wt% alcohol is impregnated into the ground wastes, which is treated with the synthetic resin.