An apparatus for treatment of rubber and plastic wastes, comprising in series an extruder for heating and melting rubber and plastic wastes to extrude the molten wastes, a decomposing section for heating the molten wastes to prepare decomposed products while optionally separating residues therefrom, a dry-distilling section for gasifying the decomposed products by dry-distillation, and a cooling section for cooling the dry-distilled products to separate gaseous materials from liquid materials.