PURPOSE: To manufacture a cylindrical material in which its physical properties are sequentially or continuously shifted toward its center by rotatably repeating a method of varying a solution composition and separating it from a polymer solution by the action of a centrifugal force.

CONSTITUTION: The rotary force of an induction motor 1 with a transmission is transmitted to the rotary shaft 4 of a cylindrical metal mold 3 through a pulley 2. An electric heater 6 is provided in contact with the mold to heat the mold. Rotary shafts 4, 5 of hollow tubes protrude from mirror plates 7 of both sides in the mold, and the hollow part 8 of the shaft 5 is used also as a material inlet and an air discharge port, and air filtered by a filter is fed from the shaft 4. For example, after MMA/MEK solution is poured in the mold while the mold is rotated at 2,000rpm at an ambient temperature, dry clean air is fed, and a MMA resin layer is formed. Then, a MS resin layer is formed wholly similarly of MS/MEK solution. Eventually, a resin layer is formed of PS/MEK solution, and a triple tube is obtained.