PURPOSE: To produce bricks by utilizing residual materials which are heretofore thrown away.

CONSTITUTION: Ash generated by combustion, more preferably annealed clay ore included in a brown coal ash, more particularly the residual material essentially consisting of dry portions are used as a material contg. lay. Water, extenders and, if necessary, other additives are added to the residual material to form a earth-moisture molding material. The molding material is compressed under a pressure of 15 to 20 N/mm2 order to form a green brick. As a result, the residual material is not used as the extender but as a substitute for the actual clay and, therefore, refuse problems may be decreased and natural resources may be saved.