An object of this invention is to provide a sealed rotary feeder for use in an apparatus which continuously processes chips made of synthetic resin with a coating under high pressure and temperature without degrading its material strength. The sealed rotary feeder according to this invention consists of a cylindrical casing having a chip inlet on the upper side of said cylindrical casing and a chip outlet on the low side of said cylindrical casing, a rotor in said cylindrical casing, plural blades which are movably inserted into channels radially formed around said rotor, and divide said cylindrical casing into plural baskets, pressing means which press said plural blades against the inner surface of said cylindrical casing, and walls which form said channels are extended at the vicinity of the inner surface of said cylindrical casing.