To provide a continuous apparatus for liquefying waste plastic into oil which can continuously treat waste plastics and simultaneously remove foreign matters.

The apparatus for liquefying waste plastic into oil is equipped with a melting tank 12 for melting waste plastics, a gasification device 13 for gasifying a melted liquid introduced from the melting tank 12, and a recycled oil-recovering portion 14 for cooling the gas produced in the gasification device 13 to recover the recycled oil. In the apparatus, a liquid-transferring conveyer 15 is disposed which comprises a screw conveyer connecting the bottom of the melting tank 12 to the gasification device 13 to transfer the melted liquid and residues, and an ash conveyer 16 is connected to the gasification device 13, which comprises a screw conveyer for scraping up and discharging the residues.