PURPOSE: To highly accurately perform predetermined work for a peripheral surface without dislocation of the center position in both end parts of a workpiece by lifting a free rotating roller in a truck side to align center height of both the end parts in the axial line direction of the workpiece to the predetermined height being based on a measuring result of a diameter in both the end parts of the workpiece.

CONSTITUTION: When both end parts of a workpiece W are stop-received onto a drum- shaped roller 12 of trucks 1, 2, a displacement amount of a height position between the center of a workpiece fixing rotary device 36 and the center of one end part in the axial line direction of the workpiece W is obtained by drive-running a carriage 6 to a position just above the one truck 1 to protrusion-move a workpiece diameter measuring device and measuring an outside diameter in one end part in the axial line direction of the workpiece W, and the center in its one end part agrees with the center of the workpiece fixing rotary device 36 by lifting a free rotating roller group by the amount corresponding to the displacement amount. Next, the center of the other end part in the axial line direction of the workpiece W agrees with the center of the workpiece fixing rotary device 36 similarly by drive-running the carriage 6 to a position just above the other truck 2.