Abstract: According to an embodiment of the present disclosure, there is provided a waste plastic gasification device including: a raw material input unit for inputting waste plastic raw materials; a first gasification unit that pyrolyzes the waste plastic raw materials at low temperatures using superheated steam to produce a mixed gas and preheats residual raw materials that have not been decomposed; a second gasification unit that further decomposes the preheated residual raw materials through plasma to produce the mixed gas; a residue discharge unit that stores and discharges waste plastic residual melt slag that has not been decomposed in the second gasification unit; and a heat exchange unit for cooling the mixed gas generated in the first gasification unit and the second gasification unit, wherein the second gasification unit is inclined in a direction of the residue discharge unit to discharge the waste plastic residual melt slag.