To provide a waste material molding device for facilitating a mixed integration of resin constituents in an extruded waste material molded body.

This waste material molding device comprises a heating means 12b for heating and fusing thermoplastic resin which is disposed around a tubular body 12a for pressure feeding a waste material containing thermoplastic resins thereinto and accommodating it therein to thereby construct a heating and fusing section 12, a heat molding section 13 for molding the waste material containing thermoplastic resins which is heated at the heating and fusing section 12 and extruding the waste material so molded, and a spiral groove 20 formed in the inner wall surface of at least either of the heating and fusing section 12 and the heat molding section 13.