PURPOSE: To prevent the peeling in the terminal part of a tube material from being generated when perforation rolling or drawing is carried out by an inclined rolling mill provided with a disk roll as a guide member.

CONSTITUTION: The terminal of the tube material 4 fed along a pass line X-X, while suppressing expansion outward by disk rolls 2, 2 and rolled by inclined rolls 2, 2 is detected by a terminal detector 7 arranged in front of the inclined rolls 1, 1 and disk rolls 2, 2 and the result is given to a controller 9. The controller 9 issues an operation command to a roll opening adjuster 5 and a guide interval adjuster 6 after a terminal detection is performed and a set time set to a setter 11 elapses. The roll opening adjuster 5 and the guide interval adjuster 6 perform an operation for increasing the roll opening and the guide interval respectively by a specified amount. In a manner, rolling in a specified range from the terminal of the tube material 4 is carried out in the roll opening and guide interval larger than another part.