To obtain moldings which are reusable as a paving stone, a tile, and a block by mixing foam waste such as a foamed synthetic resin with pulverized sand and glass, halfway in the passage of the foam waste through an upper and a lower heating cylinder of a double stage structure.

An upper and a lower heating cylinder 2, 6 of a double stereostructure type are installed and the upper-stage heating cylinder 2 has a first hopper 1 for supplying synthetic resin foam waste connected to the end part of the cylinder 3 on the top. In addition, a top die 3 is provided on the upper-stage heating cylinder 3 and at the same time, an inducing guide cylinder 5 for guiding a molten material flowing down from the top die 3 is installed upright. Further, the lower end of the inducing guide cylinder 5 is connected to the lower-stage heating cylinder 6. The lower-stage heating cylinder 6 has a second hopper 7 of injecting pulverized sand and glass or particle provided upright on the end part of the lower-stage heating cylinder 6. At the same time, a band heater is wound below the second hopper 7 and a mixed half-molten resin from the lower-stage heating cylinder 6 is molded by a synthetic resin molding machine 15 through a receiving tray 14.